Organic electroluminescent devices and metal complex compounds

ABSTRACT

An organic electroluminescent device, which has a pair of electrodes and at least one organic layer including a luminescent layer between the pair of electrodes, wherein at least one layer between the pair of electrodes comprises at least one metal complex having a tridentate- or higher polydentate-chain structure ligand.

This application is a Divisional Application of Application No.10/551,653 filed on Sep. 29, 2005, now U.S. Pat. No. 7,569,692, forwhich priority is claimed under 35 USC 120, and which is a 371 ofPCT/JP04/07882, filed on Jun. 1, 2004; and this application claimspriority of Application No. 2003-157006 filed in Japan on Jun. 2, 2003and 2004-092274 filed in Japan on Mar. 26, 2004.

TECHNICAL FIELD

The present invention relates to organic electroluminescent devices(luminescent devices or EL devices) to convert electric energy intolight. Further, the present invention relates to metal complexes to beused suitably in the organic electroluminescent devices.

BACKGROUND ART

Recently, a variety of types of display devices are actively researchedand developed. Among these, much attention is focused on organicelectroluminescent (EL) devices. This is because organic EL devices arepromising display devices capable of emitting light of high luminanceunder low applied voltage.

Recently, application of organic EL devices to color displays and whitelight sources has been actively studied. However, development onhigh-grade color displays and white light sources requires enhancing thecharacteristics (performances) of blue-, green-, and red-emittingdevices.

On the other hand, as luminescent devices using a red-emittingphosphorescent material, those using a cyclic tetradentateligand-containing platinum porphyrin complex as a light-emittingmaterial are known by, for example, Nature 395, 151 (1998) and U.S. Pat.No. 6,303,231 B1. However, because these devices are low in maximumluminance (brightness), enhancement of the maximum luminance has beendesired.

Further, there are reports on platinum porphyrin complexes containing abipyridine-series or phenanthroline-series chain tetradentate ligand(see Chem. Eur. J., 9, No. 6, 1264 (2003), U.S. Pat. No. 6,653,654 B1and WO 03/093283A1). However, these complexes do not compatibly satisfyboth durability and luminous characteristics, such as color purity.Accordingly, improvement on these properties is desired. Also withrespect to green-emitting luminescent materials and blue-emittingluminescent materials that emit in a shorter wavelength region than theaforementioned luminescent materials, there is a need for development ofadvanced materials that are excellent in both luminous characteristicsand durability.

DISCLOSURE OF THE INVENTION

According to the present invention, there are provided the followingmeans:

-   [1] An organic electroluminescent device, comprising a pair of    electrodes, and at least one organic layer including a luminescent    layer between the pair of electrodes, wherein at least one layer    between the pair of electrodes comprises at least one metal complex    having a tridentate- or higher polydentate-chain structure ligand.-   [2] The organic electroluminescent device described in [1], wherein    a metal ion in the metal complex is selected from the group    consisting of platinum, iridium, rhenium, palladium, rhodium,    ruthenium and copper ions.-   [3] The organic electroluminescent device described in [1] or [2],    wherein the metal complex has no carbon-metal bond.-   [4] The organic electroluminescent device described in any one of    [1] to [3], wherein the metal complex is a phosphorescent emissive    metal complex, and said metal complex is incorporated in the    luminescent layer.-   [5] The organic electroluminescent device described in any one of    [1] to [4], wherein the metal complex is a compound represented by    formula (1):

wherein, M¹¹ represents a metal ion; L¹¹, L¹², L¹³, L¹⁴, and L¹⁵ eachrepresent a ligand to coordinate to M¹¹; L¹¹ and L¹⁴ do not combinetogether via an atomic group, to form a cyclic ligand; L¹⁵ does not bondto both L¹¹ and L¹⁴, to form a cyclic ligand; Y¹¹, Y¹², and Y¹³ eachrepresent a linking group, a single bond, or a double bond; a bondbetween L¹¹ and Y¹², a bond between Y¹² and L¹², a bond between L¹² andY¹¹, a bond between Y¹¹ and L¹³, a bond between L¹³ and Y¹³, and a bondbetween Y¹³ and L¹⁴ each represent a single bond, or a double bond; n¹¹represents 0 to 4.

-   [6] The organic electroluminescent device described in any one of    [1] to [5], wherein the metal complex is a compound represented by    formula (2):

wherein, M²¹ represents a metal ion; Y²¹ represents a linking group, asingle bond, or a double bond; Y²² and Y²³ each represent a single bondor a linking group; Q²¹ and Q²² each represent an atomic group necessaryto form a nitrogen-containing heterocycle; a bond between Y²¹ and thering formed with Q²¹, and a bond between Y²¹ and the ring formed withQ²² each represent a single bond, or a double bond; X²¹ and X²² eachrepresent an oxygen atom, a sulfur atom, or a substituted orunsubstituted nitrogen atom; R²¹, R²², R²³, and R²⁴ each represent ahydrogen atom, or a substituent; R²¹ and R²², and R²³ and R²⁴,respectively, may bond to each other to form a ring; L²⁵ represents aligand to coordinate to M²¹; n²¹ represents an integer of 0 to 4.

-   [7] The organic electroluminescent device described in [6], wherein    the metal complex is a compound represented by formula (2) in which    the ring formed with Q²¹ and the ring formed with Q²² each are a    pyridine ring, and Y²¹ represents a linking group composed of at    least one atom.-   [8] The organic electroluminescent device described in [6], wherein    the metal complex is a compound represented by formula (2) in which    the ring formed with Q²¹ and the ring formed with Q₂₂ each are a    pyridine ring, Y²¹ represents a single bond or a double bond, and    X²¹ and X²² each represent a sulfur atom or a substituted or    unsubstituted nitrogen atom.-   [9] The organic electroluminescent device described in [6], wherein    the metal complex is a compound represented by formula (2) in which    the ring formed with Q²¹ and the ring formed with Q²² each are a    5-membered nitrogen-containing heterocycle.-   [10] The organic electroluminescent device described in [6], wherein    the metal complex is a compound represented by formula (2) in which    the ring formed with Q²¹ and the ring formed with Q²² each are a    6-membered heterocycle containing at least two nitrogen atoms.-   [11] The organic electroluminescent device described in [1] or [2],    wherein the metal complex is a compound represented by formula (9):

wherein, M^(A1) represents a metal ion; Q^(A1) and Q^(A2) each representan atomic group necessary to form a nitrogen-containing heterocycle;R^(A1), R^(A2), R^(A3), and R^(A4) each represent a hydrogen atom, or asubstituent; R^(A1) and R^(A2), and R^(A3) and R^(A4), respectively, maybond to each other to form a ring; Y^(A2) and Y^(A3) each represent alinking group or a single bond; Y^(A1) represents a linking group, asingle bond or double bond for linking two bidentate ligands inparentheses together; L^(A5) represents a ligand to coordinate toM^(A1); n^(A1) represents an integer of 0 to 4.

-   [12] The organic electroluminescent device described in [1] or [2],    wherein the metal complex is a compound represented by formula (10):

wherein, M^(B1) represents a metal ion; Y^(B1) represents a linkinggroup; Y^(B2) and Y^(B3) each represent a linking group or a singlebond; X^(B1) and X^(B2) each represent an oxygen atom, a sulfur atom, ora substituted or unsubstituted nitrogen atom; n^(B1) and n^(B2) eachrepresent an integer of 0 to 1; R^(B1), R^(B2), R^(B3), R^(B4), R^(B5),and R^(B6) each represent a hydrogen atom, or a substituent; R^(B1) andR^(B2), and R^(B3) and R^(B4), respectively, may bond to each other toform a ring; L^(B5) represents a ligand to coordinate to M^(B1); n^(B3)represents an integer of 0 to 4; and Y^(B1) does not link to R^(B5) orR^(B6).

-   [13] The organic electroluminescent device described in any one of    [1] to [4], wherein the metal complex is a compound represented by    formula (8):

wherein, M⁸¹ represents a metal ion; L⁸¹, L⁸², L⁸³, and L⁸⁵ eachrepresent a ligand to coordinate to M⁸¹; L⁸¹ and L⁸³ do not combinetogether via an atomic group, to form a cyclic ligand or a tetradentateor higher-polydentate ligand; L⁸⁵ does not directly bond to L⁸¹ or L⁸³,but bonds to via the metal; Y⁸¹ and Y⁸² each represent a linking group,a single bond, or a double bond; n⁸¹ represents an integer of 0 to 3.

-   [14] The organic electroluminescent device described in [13],    wherein the metal complex is a compound represented by formula (8)    in which L⁸¹, L⁸², and L⁸³ each represent an aromatic carbocycle or    heterocycle to coordinate to M⁸¹ via a carbon atom, or a    nitrogen-containing heterocycle to coordinate to M⁸¹ via a nitrogen    atom, and at least one of L⁸¹, L⁸², and L⁸³ is said    nitrogen-containing heterocycle.-   [15] The organic electroluminescent device described in [1] or [2],    wherein the metal complex is a compound represented by formula (X1):

wherein, M^(X1) represents a metal ion; Q^(X11), Q^(X12), Q^(X13),Q^(X14), Q^(X15), and Q^(X16) each represent an atom to coordinate toM^(X1) or an atomic group having an atom to coordinate to M^(X1);L^(X11), L^(X12), L^(X13), and L^(X14) each represent a single bond, adouble bond, or a linking group; an atomic group consisted ofQ^(X11)-L^(X1)-Q^(X12)-L^(X12)-Q^(X13) and an atomic group consisted ofQ^(X14)-L^(X13)-Q^(X15)-L^(X14)-Q^(X16) each represent a tridentateligand; and a bond between M^(X1) and Q^(X11), a bond between M^(X1) andQ^(X12), a bond between M^(X1) and Q^(X13), a bond between M^(X1) andQ^(X14), a bond between M^(X1) and Q^(X15), and a bond between M^(X1)and Q^(X16) each are a coordinate bond or a covalent bond.

-   [16] The organic electroluminescent device described in [15],    wherein the metal complex represented by formula (X1) is a compound    represented by formula (X2):

wherein, M^(X2) represents a metal ion; Y^(X21), Y^(X22), Y^(X23),Y^(X24), Y^(X25), and Y_(X26) each represent an atom to coordinate toM^(X2); each of Q^(X21), Q^(X22), Q^(X23), Q^(X24), Q^(X25), and Q^(X26)respectively represents an atomic group necessary to form an aromaticring or heterocyclic ring together with each of Y^(X21), Y^(X22),Y^(X23), Y^(X24), Y^(X25), and Y^(X26), respectively; L^(X21), L^(X22),L^(X23), and L^(X24) each represent a single bond, a double bond, or alinking group; and a bond between a bond between M^(X2) and Y^(X21), abond between M^(X2) and Y^(X22), a bond between M^(X2) and Y^(X23), abond between M^(X2) and Y^(X24), a bond between M^(X2) and Y^(X25), anda bond between M^(X2) and Y^(X26) each are a coordinate bond or acovalent bond.

-   [17] The organic electroluminescent device described in [15],    wherein the metal complex represented by formula (X1) is a compound    represented by formula (X3):

wherein, M^(X3) represents a metal ion; Y^(X31), Y^(X32), Y^(X33),Y^(X34), Y^(X35), and Y^(X36) each represent a carbon atom, a nitrogenatom, or a phosphorus atom; L^(X31), L^(X32), L^(X33), and L^(X34) eachrepresent a single bond, a double bond, or a linking group; and a bondbetween M^(X3) and Y^(X31), a bond between M^(X3) and Y^(X32), a bondbetween M^(X3) and Y^(X33), a bond between M^(X3) and Y^(X34), a bondbetween M^(X3) and Y^(X35), and a bond between M^(X3) and Y^(X36) eachare a coordinate bond or a covalent bond.

-   [18] The organic electroluminescent device described in any one of    [1] to [17], wherein the organic layer comprises at least one    luminescent layer and a hole transporting layer, and the organic    layer further comprises at least one layer selected from the group    consisting of an exciton-blocking layer, a hole injection layer, a    hole-blocking layer and an electron-transporting layer.-   [19] The organic electroluminescent device described in any one of    [1] to [18], wherein the organic layer comprises at least one    luminescent layer, and a host material of the luminescent layer is    selected from the group consisting of an amine compound, a metal    chelate oxynoid compound (i.e. a compound having a metal-oxygen    bond) in which the metal is aluminum, zinc or transition metals, a    polyarylene compound, a condensed aromatic carbocyclic compound, and    a non-complex aromatic heterocyclic compound.-   [20] The organic electroluminescent device described in any one of    [1] to [19], wherein the organic layer comprises at least one    electron-transporting layer in which an electron-transporting    material is selected from the group consisting of a metal chelate    oxynoid compound, a polyarylene compound, a condensed aromatic    carbocyclic compound and a non-complex aromatic heterocyclic    compound.-   [21] The organic electroluminescent device described in any one of    [1] to [20], wherein the organic layer comprises at least one    luminescent layer, and a host material of the luminescent layer is    composed of at least two compounds.-   [22] A compound represented by formula (11):

wherein, R^(C1) and R^(C2) each represent a hydrogen atom or asubstituent; R^(C3), R^(C4), R^(C5), and R^(C6) each represent asubstituent; n^(C3) and n^(C6) each represent an integer of 0 to 3;n^(C4) and n^(C5) each represent an integer of 0 to 4; when a pluralityof R^(C3), R^(C4), R^(C5) or R^(C6) exists, the respective R^(C3)s,R^(C4)s, R^(C5)s or R^(C6)s may be the same or different from eachother, and, respectively, the R^(C3)s, R^(C4)s, R^(C5)s, or R^(C6)s maybond to each other to form a condensed ring.

-   [23] A compound represented by formula (12):

wherein, R^(D3) and R^(D4) each represent a hydrogen atom or asubstituent; R^(D1) and R^(D2) each represent a substituent; n^(D1) andn^(D2) each represent an integer of 0 to 4; when a plurality of R^(D1)or R^(D2) exists, the respective R^(D1)s or R^(D2)s may be the same ordifferent from each other, and, respectively, the R^(D1)s or R^(D2)s maybond to each other to form a ring; and Y^(D1) represents a vinyl groupthat substitutes with 1- and 2-positions, a phenylene group, a pyridinering, a pyrazine ring, a pyrimidine ring or a methylene group having 1to 8 carbon atoms.

-   [24] A compound represented by formula (X1):

wherein, M^(X1) represents a metal ion; Q^(X11), Q^(X12), Q^(X13),Q^(X14), Q^(X15), and Q^(X16) each represent an atom to coordinate toM^(X1) or an atomic group having an atom to coordinate to M^(X1);L^(X11), L^(X12), L^(X13), and L^(X14) each represent a single bond, adouble bond, or a linking group; an atomic group consisted ofQ^(X11)-L^(X11)-Q^(X12)-L^(X12)-Q^(X13) and an atomic group consisted ofQ^(X14)-L^(X13)-Q^(X15)-L^(X14)-Q^(X16) each represent a tridentateligand; and a bond between M^(X1) and Q^(X11), a bond between M^(X1) andQ^(X12), a bond between M^(X1) and Q^(X13), a bond between M^(X1) andQ^(X14), a bond between M^(X1) and Q^(X15), and a bond between M^(X1)and Q^(X16) each are a coordinate bond or a covalent bond.

-   [25] A compound represented by formula (X2):

wherein, M^(X2) represents a metal ion; Y^(X21), Y^(X22), Y^(X23),Y^(X24), Y^(X25), and Y^(X26) each represent an atom to coordinate toM^(X2); each of Q^(X21), Q^(X22), Q^(X23), Q^(X24), Q^(X25), and Q^(X26)respectively represents an atomic group necessary to form an aromaticring or heterocyclic ring together with each of Y^(X21), Y^(X22),Y^(X23), Y^(X24), Y^(X25), and Y^(X26), respectively; L^(X21), L^(X22),L^(X23), and L^(X24) each represent a single bond, a double bond, or alinking group; and a bond between M^(X2) and Y^(X21), a bond betweenM^(X2) and Y^(X24), a bond between M^(X2) and Y^(X25), a bond betweenM^(X2) and Y^(X24), a bond between M^(X2) and Y^(X25), and a bondbetween M^(X2) and Y^(X26) each are a coordinate bond or a covalentbond.

-   [26] A compound represented by formula (X3):

wherein, M^(X3) represents a metal ion; Y^(X31), Y^(X32), Y^(X33),Y^(X34), Y^(X35), and Y^(X36) each represent a carbon atom, a nitrogenatom, or a phosphorus atom; L^(X31), L^(X32), L^(X33), and L^(X34) eachrepresent a single bond, a double bond, or a linking group; and a bondbetween M^(X3) and Y^(X31), a bond between M^(X3) and Y^(X32), a bondbetween M^(X3) and Y^(X33), a bond between M^(X3) and Y^(X34), a bondbetween M^(X3) and Y^(X35), and a bond between M^(X3) and Y^(X36) eachare a coordinate bond or a covalent bond.

The term “chain ligand” used in this specification means ligands exceptcyclic ligands such as porphyrin and phthalocyanine. Taken formula (8)as an example, said term means such ligands that L⁸¹ and L⁸³ do notdirectly connect but are bound via Y⁸¹, L⁸², Y⁸², and M⁸¹. Even in thecase where L⁸¹, Y⁸¹, L⁸², Y⁸², or L⁸³ contains a ring structure such asbenzene, pyridine, and quinoline, the ligand is referred to as a chainligand, as long as L⁸¹ and L⁸³ do not directly combine but combine viaY⁸¹, L⁸², Y⁸², and M⁸¹. An additional atomic group may exist between L⁸¹and Y⁸¹, or Y⁸¹ and L⁸² or L⁸² and Y⁸², or Y⁸² and L⁸³, to form a ring.

Other and further features and advantages of the invention will appearmore fully from the following description.

BEST MODE FOR CARRYING OUT THE INVENTION

The organic electroluminescent device of the present invention(hereinafter sometimes referred to as a device of the present invention)is characterized in that the device contains a pair of electrodes and atleast one organic layer including a luminescent layer (the organic layermay consist of organic compounds, or may additionally contain inorganiccompounds), between the pair of electrodes, in which any layer betweenthe pair of electrodes contains a phosphorescent emissive metal complexhaving a tridentate- or higher polydentate-chain ligand.

As the metal complex having a tridentate- or higher polydentate-chainligand for use in the present invention (hereinafter sometimes referredto as a metal complex of the present invention), metal complexes havingfrom tridentate- to octadentate-chain ligand are preferable, metalcomplexes having from tetradentate- to octadentate-chain ligand are morepreferable, metal complexes having from tetradentate- tohexadentate-chain ligand are furthermore preferable, and metal complexeshaving tetradentate-chain ligand are most preferable.

The chain ligand for use in the present invention preferably contains atleast one nitrogen-containing heterocycle (e.g., pyridine, quinoline,pyrrole rings) to coordinate to the central metal {if formula (1) istaken as an example, said metal is represented by M¹¹} via a nitrogenatom.

It is preferable for the metal complex of the present invention not tohave a carbon-metal bond. Namely it is preferable that there is no bondbetween a metal atom and a carbon atom in the metal complex.Specifically illustrating about the term “not to have a carbon-metalbond”, the metal compound preferably has any of the bonds describedbelow. That is, a metal-nitrogen bond, a metal-oxygen bond, ametal-sulfur bond, a metal-phosphorus bond, and a metal-selenium bondare preferable. A metal-nitrogen bond, a metal-oxygen bond, ametal-sulfur bond, and a metal-phosphorus bond are more preferable. Ametal-nitrogen bond, a metal-oxygen bond, and a metal-sulfur bond arefurthermore preferable.

The compound for use in the present invention is not particularlyrestricted, so long as the compound is a phosphorescent emissivecompound. Preferred are compounds to emit phosphorescence preferably atnot less than −30° C., more preferably at not less than −10° C.,furthermore preferably at not less than 0° C., and particularlypreferably at not less than 10° c. The compound may emit fluorescence atthe same time. In this case, preferred are compound whose intensity ofphosphorescence at 20° C. is not less than 2 times, more preferably notless than 10 times, furthermore preferably not less than 100 times, theintensity of fluorescence.

It is preferable for the phosphorescent material for use in the presentinvention to have a phosphorescent quantum yield (20° C.) of not lessthan 10% and the phosphorescent λmax (phosphorescent emission maximum)in the range of from 400 nm to 700 nm, more preferably a phosphorescentquantum yield (20° C.) of not less than 15% and the phosphorescent λmaxin the range of from 400 nm to 575 nm, and furthermore preferably aphosphorescent quantum yield (20° C.) of not less than 20% and thephosphorescent λmax in the range of from 400 nm to 560 nm.

The metal complex of the present invention is incorporated in any layerbetween a pair of electrodes, preferably it is incorporated in a holeinjection/hole transporting layer and/or a luminescent layer(light-emitting layer), and more preferably in a luminescent layer. Inthe case where the metal complex of the present invention isincorporated in the luminescent layer, a density of the phosphorescentemissive compound in the luminescent layer is preferably in the range offrom 1 to 30% by mass, more preferably in the range of from 2 to 20% bymass, and further more preferably in the range of from 3 to 15% by mass,based on the mass of the luminescent layer respectively.

A preferable embodiment of the metal complex of the present inventionhaving a tetradentate or higher polydentate ligand is represented byformula (1). The preferable embodiment of the metal complex representedby formula (1) is one represented by formula (2), (5), (9), or (10).

A preferable embodiment of the metal complex represented by formula (2)is one represented by formula (3).

A preferable embodiment of the metal complex represented by formula (9)is one represented by formula (6) or (7), and a preferable embodiment ofthe metal complex represented by formula (7) is one represented byformula (11).

A preferable embodiment of the metal complex represented by formula (10)is one represented by formula (12).

In the following, the compound represented by formula (1) will bedescribed.

M¹¹ represents a metal ion. The metal ion is not particularlyrestricted, but divalent or trivalent metal ions are preferable. As thedivalent or trivalent metal ions, platinum, iridium, rhenium, palladium,rhodium, ruthenium, copper, europium, gadolinium, and terbium ions arepreferable. Of these ions, platinum, iridium and europium ions are morepreferable; platinum and iridium ions are furthermore preferable; and aplatinum ion is particularly preferable.

L¹¹, L¹², L¹³, and L¹⁴ each represent a ligand to coordinate to M¹¹. Asthe atom that is contained in L¹¹, L¹², L¹³, or L¹⁴ and coordinates toM¹¹, nitrogen, oxygen, sulfur, and carbon atoms are preferable, andnitrogen, oxygen and carbon atoms are more preferable.

The bond to be formed between M¹¹ and L¹¹, L¹², L¹³, or L¹⁴ may be acovalent bond, an ion bond, or a coordination bond. The ligand that iscomposed of L¹¹, Y¹², L¹², Y¹¹, L¹³, Y¹³, and L¹⁴ is preferably ananionic ligand (i.e., a ligand that bonds to a metal with at least oneanion of the ligand). The number of anions in the anionic ligand ispreferably 1 to 3, more preferably 1 or 2, and furthermore preferably 2.

L¹¹, L¹², L¹³, or L¹⁴ to coordinate to M¹¹ via a carbon atom, is notparticularly restricted. Examples of these ligands include iminoligands, aromatic carbocyclic ligands (for example, benzene,naphthalene, anthracene, phenanthracene ligands), heterocyclic ligands{for example, thiophene, pyridine, pyrazine, pyrimidine, thiazole,oxazole, pyrrole, imidazole, pyrazole ligands, condensed ringscontaining these rings (e.g., quinoline, benzothiazole ligands), andtautomers of these rings}.

L¹¹, L¹², L¹³, or L¹⁴ to coordinate to M¹¹ via a nitrogen atom is notparticularly restricted. Examples of these ligands includenitrogen-containing heterocyclic ligands {for example, pyridine,pyrazine, pyrimidine, pyridazine, triazine, thiazole, oxazole, pyrrole,imidazole, pyrazole, triazole, oxadiazole, and thiadiazole ligands,condensed rings containing any of these ligands (e.g., quinoline,benzoxazole, benzimidazole ligands), and tautomers of these ligands (thetautomers are defined in the present invention as it means that thefollowing examples are also embraced in the tautomer in addition toordinary tautomers; for example, the 5-membered heterocyclic ligand ofcompound (24), the terminal 5-membered heterocyclic ligand of compound(64), and a 5-membered heterocyclic ligand of compound (145) are definedas pyrrole tautomers)}, and amino ligands {for example, alkylaminoligands (those having carbon atoms preferably in the range of 2 to 30,more preferably in the range of 2 to 20, and particularly preferably inthe range of 2 to 10; for example, methylamino), arylamino ligands (forexample, phenylamino), acylamino ligands (those having carbon atomspreferably in the range of 2 to 30, more preferably in the range of 2 to20, and particularly preferably in the range of 2 to 10; for example,acetylamino, benzoylamino), alkoxycarbonylamino ligands (those havingcarbon atoms preferably in the range of 2 to 30, more preferably in therange of 2 to 20, and particularly preferably in the range of 2 to 12;for example, methoxycarbonylamino), aryloxycarbonylamino ligands (thosehaving carbon atoms preferably in the range of 7 to 30, more preferablyin the range of 7 to 20, and particularly preferably in the range of 7to 12; for example, phenyloxycarbonylamino), sulfonylamino ligands(those having carbon atoms preferably in the range of 1 to 30, morepreferably in the range of 1 to 20, and particularly preferably in therange of 1 to 12; for example, methane sulfonylamino, benzenesulfonylamino), imino ligands}. These ligands may be further substitutedwith a substituent.

L¹¹, L¹², L¹³, or L¹⁴ to coordinate to M¹¹ via an oxygen atom is notparticularly restricted. Examples of these ligands include alkoxyligands (those having carbon atoms preferably in the range of 1 to 30,more preferably in the range of 1 to 20, and particularly preferably inthe range of 1 to 10; for example, methoxy, ethoxy, butoxy,2-ethylhexyloxy), aryloxy ligands (those having carbon atoms preferablyin the range of 6 to 30, more preferably in the range of 6 to 20, andparticularly preferably in the range of 6 to 12; for example, phenyloxy,1-naphthyloxy, 2-naphthyloxy), heterocyclic oxy ligands (those havingcarbon atoms preferably in the range of 1 to 30, more preferably in therange of 1 to 20, and particularly preferably in the range of 1 to 12;for example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy), acyloxyligands (those having carbon atoms preferably in the range of 2 to 30,more preferably in the range of 2 to 20, and particularly preferably inthe range of 2 to 10; for example, acetoxy, benzoyloxy), silyloxyligands (those having carbon atoms preferably in the range of 3 to 40,more preferably in the range of 3 to 30, and particularly preferably inthe range of 3 to 24; for example, trimethylsilyloxy, triphenylsilyloxy), carbonyl ligands (for example, ketone ligands, ester ligands,amide ligands), and ether ligands (for example, dialkylether ligands,diarylether ligands, furyl ligands).

L¹¹, L¹², L¹³, or L¹⁴ to coordinate to M¹¹ via a sulfur atom is notparticularly restricted. Examples of these ligands include alkylthioligands (those having carbon atoms preferably in the range of 1 to 30,more preferably in the range of 1 to 20, and particularly preferably inthe range of 1 to 12; for example, methylthio, ethylthio), arylthioligands (those having carbon atoms preferably in the range of 6 to 30,more preferably in the range of 6 to 20, and particularly preferably inthe range of 6 to 12; for example, phenylthio), heterocyclic thioligands (those having carbon atoms preferably in the range of 1 to 30,more preferably in the range of 1 to 20, and particularly preferably inthe range of 1 to 12; for example, pyridylthio, 2-benzimidazolylthio,2-benzoxazolylthio, 2-benzthiazolylthio), thiocarbonyl ligands (forexample, thioketone ligands, thioester ligands), and thioether ligands(for example, dialkylthioether ligands, diarylthioether ligands,thiofuryl ligands). Further, these ligands may be further substitutedwith a substituent.

Preferably, L¹¹ and L¹⁴ each are an aromatic carbocyclic ligand, analkyloxy ligand, an aryloxy ligand, an ether ligand, an alkylthioligand, an arylthio ligand, an alkylamino ligand, an arylamino ligand,an acylamino ligand, and a nitrogen-containing heterocyclic ligand (forexample, pyridine, pyrazine, pyrimidine, pyridazine, triazine, thiazole,oxazole, pyrrole, imidazole, pyrazole, triazole, oxadiazole, andthiadiazole ligands; a condensed ligand containing any of these ligands(e.g., quinoline, benzoxazole, benzimidazole ligands); and a tautomer ofany of these ligands). Of these ligands, an aromatic carbocyclic ligand,an aryloxy ligand, an arylthio ligand, an arylamino ligand, a pyridineligand, a pyrazine ligand, an imidazole ligand, a condensed ligandcontaining any of these ligands (e.g., quinoline, quinoxaline,benzimidazole ligands); and a tautomer of any of these ligands are morepreferable. An aromatic carbocyclic ligand, an aryloxy ligand, anarylthio ligand, and an arylamino ligand are furthermore preferable withthe aromatic carbocyclic ligand and aryloxy ligand being mostpreferable.

L¹² and L¹³ each are preferably a ligand to form a coordinate bond withM¹¹. As the ligand to form a coordinate bond with M¹¹, a pyridine ring,a pyrazine ring, a pyrimidine ring, a triazine ring, a thiazole ring, anoxazole ring, a pyrrole ring, a triazole ring, a condensed ringcontaining any of these rings (e.g., quinoline, benzoxazole,benzimidazole, and indolenine rings); and a tautomer of any of theserings are preferable. Of these, a pyridine ring, a pyrazine ring, apyrimidine ring, a pyrrole ring, a condensed ring containing any ofthese rings (e.g., quinoline, benzpyrrole rings); and a tautomer of anyof these rings are preferable. A pyridine ring, a pyrazine ring, apyrimidine ring, and a condensed ring containing any of these rings(e.g., a quinoline ring) are more preferable. A pyridine ring and acondensed ring containing a pyridine ring (e.g., a quinoline ring) areparticularly preferable.

L¹⁵ represents a ligand to coordinate to M¹¹. L¹⁵ is preferably amonodentate to tetradentate ligand, more preferably an anionic,monodentate to tetradentate ligand. The anionic, monodentate totetradentate ligand is not particularly restricted, but it is preferablya halogen ligand, a 1,3-diketone ligand (e.g., acetylacetone ligand), amonoanionic bidentate ligand containing a pyridine ligand (e.g.,picolinic acid, 2-(2-hydroxyphenyl)-pyridine ligands), and atetradentate ligand formed with L¹¹, Y¹², L¹², Y¹¹, L¹³, Y¹³, and L¹⁴;more preferably a 1,3-diketone ligand (e.g., acetylacetone ligand), amonoanionic bidentate ligand containing a pyridine ligand (e.g.,picolinic acid, 2-(2-hydroxyphenyl)-pyridine ligands), and atetradentate ligand formed with L¹¹, Y¹², L¹², Y¹¹, L¹³, Y¹³, and L¹⁴;furthermore preferably a 1,3-diketone ligand (e.g., acetylacetoneligand), and a monoanionic bidentate ligand containing a pyridine ligand(e.g., picolinic acid, 2-(2-hydroxyphenyl)-pyridine ligands); andparticularly preferably a 1,3-diketone ligand (e.g., acetylacetoneligand). The coordination numbers and ligand numbers do not exceed thecoordination number of the metal. L¹⁵ does not bond to both L¹¹ and L¹⁴,to form a cyclic ligand together with them.

Y¹¹, Y¹², and Y¹³ each represent a linking group, a single bond or adouble bond. The linking group is not particularly restricted. Examplesof the linking group include a carbonyl linking group, a thiocarbonyllinking group, an alkylene group, an alkenylene group, an arylene group,a heteroarylene group, an oxygen atom-linking group, an nitrogenatom-linking group, a silicon atom-linking group, and a linking groupcomprising a combination of these groups. A bond between L¹¹ and Y¹², abond between Y¹² and L¹², a bond between L¹² and Y¹¹, a bond between Y¹¹and L¹³, a bond between L¹³ and Y¹³ and a bond between Y¹³ and L¹⁴ eachrepresent a single bond, or a double bond.

Y¹¹, Y¹², and Y¹³ each are preferably a single bond, a double bond, acarbonyl linking group, an alkylene linking group or an alkenylenegroup. Y¹¹ is more preferably a single bond or an alkylene group, andfurthermore preferably an alkylene group. Y¹² and Y¹³ each are morepreferably a single bond or an alkenylene group, and furthermorepreferably a single bond.

The member numbers of the ring formed by Y¹², L¹¹, L¹², and M¹¹, thering formed by Y¹¹, L¹², L¹³, and M¹¹, and the ring formed by Y¹³, L¹³,L¹⁴ and M¹¹ each are preferably in the range of from 4 to 10, morepreferably in the range of from 5 to 7, and furthermore preferably 5 or6.

n¹¹ represents 0 to 4. When M¹¹ is a metal that has a coordinationnumber of 4, n is 0. When M¹¹ is a metal that has a coordination numbersof 6, n¹¹ is preferably 1 or 2, more preferably 1. When M¹¹ is a metalthat has a coordination number of 6 and n¹¹ is 1, L¹⁵ represents abidentate ligand. When M¹¹ is a metal that has a coordination number of6 and n¹¹ is 2, L¹⁵ represents a monodentate ligand. When M¹¹ is a metalthat has a coordination number of 8, n¹¹ is preferably 1 to 4, morepreferably 1 or 2, and furthermore preferably 1. When M¹¹ is a metalthat has a coordination number of 8 and n¹¹ is 1, L¹⁵ represents atetradentate ligand, whereas when n¹¹ is 2, L¹⁵ represents a bidentateligand. When n is 2 or more, plural L¹⁵s may be the same or differentfrom each other.

Next, the compound represented by formula (2) will be described.

M²¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

Q²¹ and Q²² each represent a group for forming a nitrogen-containingheterocycle (a ring containing a nitrogen atom that coordinates to M²¹).The nitrogen-containing heterocycle formed by Q²¹ or Q²² is notparticularly limited, and examples include a pyridine ring, a pyrazinering, a pyrimidine ring, a triazine ring, a thiazole ring, an oxazolering, a pyrrole ring, a triazole ring, a condensed ring containing anyof these rings (e.g., quinoline, benzoxazole, benzimidazole, andindolenine rings); and a tautomer of these rings.

The nitrogen-containing heterocycle formed by Q²¹ or Q²² is preferably apyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, atriazine ring, a pyrazole ring, an imidazole ring, an oxazole ring, apyrrole ring, a benzazole ring, a condensed ring containing any of theserings (e.g., quinoline, benzoxazole, and benzimidazole rings); and atautomer of any of these rings. The nitrogen-containing heterocycleformed by Q²¹ or Q²² is more preferably a pyridine ring, a pyrazinering, a pyrimidine ring, an imidazole ring, a pyrrole ring, a condensedring containing any of these rings (e.g., quinoline ring); and atautomer of any of these rings. The nitrogen-containing heterocycleformed by Q²¹ or Q²² is further preferably a pyridine ring, a condensedring containing a pyridine ring (e.g., quinoline ring); and particularlypreferably a pyridine ring.

X²¹ and X²² each are preferably an oxygen atom, a sulfur atom, or asubstituted or unsubstituted nitrogen atom. They each are morepreferably an oxygen atom, a sulfur atom, or a substituted nitrogenatom; further preferably an oxygen atom or a sulfur atom; andparticularly preferably an oxygen atom.

Y²¹ has the same meaning as that of the aforementioned Y¹¹, with thesame preferable range.

Y²² and Y²³ each represent a single bond or a linking group, andpreferably a single bond. The linking group is not particularlyrestricted. Examples of the linking group include a carbonyl-linkinggroup, a thiocarbonyl-linking group, an alkylene group, an alkenylenegroup, an arylene group, a hetero arylene group, an oxygen atom-linkinggroup, a nitrogen atom-linking group, and a linking group formed by acombination of any of these linking groups.

As the aforementioned linking group, a carbonyl linking group, analkylene linking group and an alkenylene linking group are preferable.Of these, a carbonyl linking group and an alkenylene linking group aremore preferable with the carbonyl-linking group being furthermorepreferable.

R²¹, R²², R²³, and R²⁴ each represent a hydrogen atom, or a substituent.The substituent is not particularly limited. Examples of the substituentinclude an alkyl group (preferably having 1 to 30 carbon atoms, morepreferably having 1 to 20 carbon atoms, and particularly preferablyhaving 1 to 10 carbon atoms, e.g., methyl, ethyl, iso-propyl,tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl,cyclohexyl), an alkenyl group (preferably having 2 to 30 carbon atoms,more preferably having 2 to 20 carbon atoms, and particularly preferablyhaving 2 to 10 carbon atoms, e.g., vinyl, allyl, 2-butenyl, 3-pentenyl),an alkynyl group (preferably having 2 to 30 carbon atoms, morepreferably having 2 to 20 carbon atoms, and particularly preferablyhaving 2 to 10 carbon atoms, e.g., propargyl, 3-pentynyl), an aryl group(preferably having 6 to 30 carbon atoms, more preferably having 6 to 20carbon atoms, and particularly preferably having 6 to 12 carbon atoms,e.g., phenyl, p-methylphenyl, naphthyl, anthranyl), an amino group(preferably having 0 to 30 carbon atoms, more preferably having 0 to 20carbon atoms, and particularly preferably having 0 to 10 carbon atoms,e.g., amino, methylamino, dimethylamino, diethylamino, dibenzylamino,diphenylamino, ditolylamino), an alkoxy group (preferably having 1 to 30carbon atoms, more preferably having 1 to 20 carbon atoms, andparticularly preferably having 1 to 10 carbon atoms, e.g., methoxy,ethoxy, butoxy, 2-ethylhexyloxy), an aryloxy group (preferably having 6to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, andparticularly preferably having 6 to 12 carbon atoms, e.g., phenyloxy,1-naphthyloxy, 2-naphthyloxy), a heterocyclic oxy group (preferablyhaving 1 to 30 carbon atoms, more preferably having 1 to 20 carbonatoms, and particularly preferably having 1 to 12 carbon atoms, e.g.,pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy), an acyl group(preferably having 1 to 30 carbon atoms, more preferably having 1 to 20carbon atoms, and particularly preferably having 1 to 12 carbon atoms,e.g., acetyl, benzoyl, formyl, pivaloyl), an alkoxycabonyl group(preferably having 2 to 30 carbon atoms, more preferably having 2 to 20carbon atoms, and particularly preferably having 2 to 12 carbon atoms,e.g., methoxycarbonyl, ethoxycarbonyl), an aryloxycarbonyl group(preferably having 7 to 30 carbon atoms, more preferably having 7 to 20carbon atoms, and particularly preferably having 7 to 12 carbon atoms,e.g., phenyloxycarbonyl), an acyloxy group (preferably having 2 to 30carbon atoms, more preferably having 2 to 20 carbon atoms, andparticularly preferably having 2 to 10 carbon atoms, e.g., acetoxy,benzoyloxy), an acylamino group (preferably having 2 to 30 carbon atoms,more preferably having 2 to 20 carbon atoms, and particularly preferablyhaving 2 to 10 carbon atoms, e.g., acetylamino, benzoylamino), analkoxycarbonylamino group (preferably having 2 to 30 carbon atoms, morepreferably having 2 to 20 carbon atoms, and particularly preferablyhaving 2 to 12 carbon atoms, e.g., methoxycarbonylamino), anaryloxycarbonylamino group (preferably having 7 to 30 carbon atoms, morepreferably having 7 to 20 carbon atoms, and particularly preferablyhaving 7 to 12 carbon atoms, e.g., phenyloxycarbonylamino), asulfonylamino group (preferably having 1 to 30 carbon atoms, morepreferably having 1 to 20 carbon atoms, and particularly preferablyhaving 1 to 12 carbon atoms, e.g., methanesulfonylamino,benzenesulfonylamino), a sulfamoyl group (preferably having 0 to 30carbon atoms, more preferably having 0 to 20 carbon atoms, andparticularly preferably having 0 to 12 carbon atoms, e.g., sulfamoyl,methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl), a carbamoyl group(preferably having 1 to 30 carbon atoms, more preferably having 1 to 20carbon atoms, and particularly preferably having 1 to 12 carbon atoms,e.g., carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl), analkyl thio group (preferably having 1 to 30 carbon atoms, morepreferably having 1 to 20 carbon atoms, and particularly preferablyhaving 1 to 12 carbon atoms, e.g., methylthio, ethylthio), an aryl thiogroup (preferably having 6 to 30 carbon atoms, more preferably having 6to 20 carbon atoms, and particularly preferably having 6 to 12 carbonatoms, e.g., phenylthio), a heterocyclic thio group (preferably having 1to 30 carbon atoms, more preferably having 1 to 20 carbon atoms, andparticularly preferably having 1 to 12 carbon atoms, e.g., pyridyl thio,2-benzimidazolyl thio, 2-benzoxazolyl thio, 2-benzthiazolyl thio), asulfonyl group (preferably having 1 to 30 carbon atoms, more preferablyhaving 1 to 20 carbon atoms, and particularly preferably having 1 to 12carbon atoms, e.g., mesyl, tosyl), a sulfinyl group (preferably having 1to 30 carbon atoms, more preferably having 1 to 20 carbon atoms, andparticularly preferably having 1 to 12 carbon atoms, e.g.,methanesulfinyl, benzenesulfinyl), a ureido group (preferably having 1to 30 carbon atoms, more preferably having 1 to 20 carbon atoms, andparticularly preferably having 1 to 12 carbon atoms, e.g., ureido,methylureido, phenylureido), a phosphoric acid amido group (preferablyhaving 1 to 30 carbon atoms, more preferably having 1 to 20 carbonatoms, and particularly preferably having 1 to 12 carbon atoms, e.g.,diethyl phosphoamido, phenyl phosphoamido), a hydroxyl group, a mercaptogroup, a halogen atom (e.g., fluorine, chlorine, bromine, iodine), acyano group, a sulfo group, a carboxyl group, a nitro group, ahydroxamic acid group, a sulfino group, a hydrazino group, an iminogroup, a heterocyclic group (preferably having 1 to 30 carbon atoms,more preferably having 1 to 12 carbon atoms, and containing a heteroatom such as nitrogen, oxygen and sulfur, specifically for example,imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino,benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl), asilyl group (preferably having 3 to 40 carbon atoms, more preferablyhaving 3 to 30 carbon atoms, and particularly preferably having 3 to 24carbon atoms, e.g., trimethylsilyl, triphenylsilyl), and a silyloxygroup (preferably having 3 to 40 carbon atoms, more preferably having 3to 30 carbon atoms, and particularly preferably having 3 to 24 carbonatoms, e.g., trimethylsilyloxy, triphenylsilyloxy). These substituentsmay be further substituted by another substituent.

Preferably, R²¹, R²², R²³, and R²⁴, each are an alkyl group, an arylgroup, a group that forms a condensed ring (for example, benzo-condensedrings, pyridine-condensed rings) by forming a bond between R²¹ and R²²,or between R²³ and R²⁴. More preferably, R²¹, R²², R²³, and R²⁴, eachare a group that forms a condensed ring (for example, benzo-condensedrings, pyridine-condensed rings) by forming a bond between R²¹ and R²²,or between R²³ and R²⁴.

L²⁵ has the same meaning as that of the aforementioned L¹⁵, with thesame preferable range.

n²¹ has the same meaning as that of the aforementioned n¹¹, with thesame preferable range.

Among metal complexes represented by formula (2), those in which thering formed by Q²¹ and the ring formed by Q²² each are a pyridine ringand Y²¹ represents a linking group; those in which the ring formed byQ²¹ and the ring formed by Q²² each are a pyridine ring, Y²² representsa single bond or a double bond and X²¹ and X²² each represent a sulfuratom or a substituted or unsubstituted nitrogen atom; and those in whichthe ring formed by Q²¹ and the ring formed by Q²² each are anitrogen-containing 5-membered heterocycle or a nitrogen-containing6-membered heterocycle containing two or more nitrogen atoms, arepreferable.

Next, the compound represented by formula (3) will be described.

M³¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

Z³¹, Z³², Z³³, Z³⁴, Z³⁵, and Z³⁶ each represent a substituted orunsubstituted carbon atom or a nitrogen atom, with the substituted orunsubstituted carbon atom being preferable. Examples of the substituenton the carbon atom include those explained in the aforementioned R²¹.Further, Z³¹ and Z³², Z³² and Z³³, Z³³ and Z³⁴, Z³⁴ and Z³⁵, Z³⁵ and Z³⁶each may bond to each other via a linking group, to form a condensedring (for example, a benzo-condensed ring, a pyridine-condensed ring).Alternatively, Z³¹ and T³¹, and Z³⁶ and T³⁸ each may bond to each othervia a linking group, to form a condensed ring (for example, abenzo-condensed ring, a pyridine-condensed ring).

As the aforementioned substituent on the carbon atom, an alkyl group, analkoxy group, an alkylamino group, an aryl group, a group to form acondensed ring (for example, a benzo-condensed ring, apyridine-condensed ring) and a halogen atom are preferable. Of these, analkylamino group, an aryl group and a group to form a condensed ring(for example, a benzo-condensed ring, a pyridine-condensed ring) aremore preferable. An aryl group and a group to form a condensed ring (forexample, a benzo-condensed ring, a pyridine-condensed ring) arefurthermore preferable. A group to form a condensed ring (for example, abenzo-condensed ring, a pyridine-condensed ring) is most preferable.

T³¹, T³², T³³, T³⁴, T³⁵, T³⁶, T³⁷ and T³⁸ each represent a substitutedor unsubstituted carbon atom or a nitrogen atom, with the substituted orunsubstituted carbon atom being preferable. Examples of the substituenton the carbon atom include those explained in the aforementioned R²¹.T³¹ and T³², T³² and T³³, T³³ and T³⁴, T³⁵ and T³⁶, T³⁶ and T³⁷, T³⁷ andT³⁸ each may bond to each other via a linking group, to form a condensedring (for example, a benzo-condensed ring).

As the aforementioned substituent on the carbon atom, an alkyl group, analkoxy group, an alkylamino group, an aryl group, a group to form acondensed ring (for example, a benzo-condensed ring, apyridine-condensed ring) and a halogen atom are preferable. Of these, anaryl group, a group to form a condensed ring (for example, abenzo-condensed ring, a pyridine-condensed ring), and a halogen atom aremore preferable. An aryl group and a halogen atom are furthermorepreferable. An aryl group is most preferable.

X³¹ and X³² have the same meanings as those of the aforementioned X²¹and X²², respectively, with the same preferable ranges.

Next, the compound represented by formula (5) will be described.

M⁵¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

Q⁵¹ and Q⁵² have the same meanings as those of the aforementioned Q²¹and Q²², respectively, with the same preferable ranges.

Q⁵³ and Q⁵⁴ each represent a group to form a nitrogen-containingheterocycle (a ring containing a nitrogen to coordinate to M⁵¹). Thenitrogen-containing heterocycle formed by Q⁵³ or Q⁵⁴ is not particularlyrestricted, but preferably a tautomer of pyrrole derivatives, a tautomerof imidazole derivatives (for example, a 5-membered heterocyclic ligandof compound (29)), a tautomer of thiazole derivatives (for example, a5-membered heterocyclic ligand of compound (30)) and a tautomer ofoxazole derivatives (for example, a 5-membered heterocyclic ligand ofcompound (31)), more preferably a tautomer of pyrrole derivatives, atautomer of imidazole derivatives and a tautomer of thiazolederivatives, furthermore preferably a tautomer of pyrrole derivativesand a tautomer of imidazole derivatives, and especially preferably atautomer of pyrrole derivatives.

Y⁵¹ has the same meaning as that of the aforementioned Y¹¹, with thesame preferable range.

L⁵⁵ has the same meaning as that of the aforementioned L¹⁵, with thesame preferable range.

n⁵¹ has the same meaning as that of the aforementioned n¹¹, with thesame preferable range.

W⁵¹ and W⁵² each are preferably a substituted or unsubstituted carbonatom or a nitrogen atom. They each are more preferably an unsubstitutedcarbon atom or a nitrogen atom; further preferably an unsubstitutedcarbon atom.

Next, the compound represented by formula (9) will be described.

M^(A1), Q^(A1), Q^(A2), Y^(A1), Y^(A2), Y^(A3), R^(A1), A², R^(A3),R^(A4), L^(A5), and n^(A1) have the same meanings as those of theaforementioned M²¹, Q²¹, Q²², Y²¹, Y²², Y²³, R²¹, R²², R²³, R²⁴, L²⁵,and n²¹ in formula (2), respectively, with the same preferable ranges.

Next, the compound represented by formula (6) will be described.

M⁶¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

Q⁶¹ and Q⁶² each represent a group to form a ring. The ring formed byQ⁶¹ or Q⁶² is not particularly restricted. As the ring, there areillustrated, for example, benzene, pyridine, pyridazine, pyrimidine,thiophene, isothiazole, furane, isoxazole rings and condensed ringsthereof.

The ring formed by Q⁶¹ or Q⁶² is preferably a benzene, pyridine,thiophene, or thiazole ring or a condensed ring thereof, more preferablya benzene or pyridine ring, or a condensed ring thereof, and furthermorepreferably a benzene ring and a condensed ring thereof.

Y⁶¹ has the same meaning as that of the aforementioned Y¹¹ with the samepreferable range.

Y⁶² and Y⁶³ each represent a linking group or a single bond. The linkinggroup is not particularly restricted. Examples of the linking groupinclude a carbonyl-linking group, a thiocarbonyl-linking group, analkylene group, an alkenylene group, an arylene group, a hetero arylenegroup, an oxygen atom-linking group, a nitrogen atom-linking group, anda linking group formed by a combination of these linking groups.

Preferably, Y⁶² and Y⁶³ each are a single bond, a carbonyl-linkinggroup, an alkylene linking group, or an alkenylene group, morepreferably they each are a single bond or an alkenylene group, andfurther more preferably a single bond.

L⁶⁵ has the same meaning as that of the aforementioned L¹⁵, with thesame preferable range.

n⁶¹ has the same meaning as that of the aforementioned n¹¹, with thesame preferable range.

Z⁶¹, Z⁶², Z⁶³, Z⁶⁴, Z⁶⁵, Z⁶⁶, Z⁶⁷, and Z⁶⁸ each represent a substitutedor unsubstituted carbon atom or a nitrogen atom with the substituted orunsubstituted carbon atom being preferable. Examples of the substituenton the carbon atom include those explained in the aforementioned R²¹.Further, Z⁶¹ and Z⁶², Z⁶² and Z⁶³, Z⁶³ and Z⁶⁴, Z⁶⁵ and Z⁶⁶, Z⁶⁶ andZ⁶⁷, Z⁶⁷ and Z⁶⁸ each may bond to each other via a linking group, toform a condensed ring (for example, a benzo-condensed ring, apyridine-condensed ring). The ring formed by Q⁶¹ or Q⁶² may bond to Z⁶¹or Z⁶⁸ respectively via a linking bond, to form a ring.

As the aforementioned substituent on the carbon atom, an alkyl group, analkoxy group, an alkylamino group, an aryl group, a group to form acondensed ring (for example, a benzo-condensed ring, apyridine-condensed ring) and a halogen atom are preferable. Of these, analkylamino group, an aryl group and a group to form a condensed ring(for example, a benzo-condensed ring, a pyridine-condensed ring) aremore preferable. An aryl group and a group to form a condensed ring (forexample, a benzo-condensed ring, a pyridine-condensed ring) arefurthermore preferable. A group to form a condensed ring (for example, abenzo-condensed ring, a pyridine-condensed ring) is most preferable.

Next, the compound represented by formula (7) will be described.

M⁷¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

Y⁷¹, Y⁷², and Y⁷³ each have the same meanings as those of theaforementioned Y⁶², with the same preferable ranges.

L⁷⁵ has the same meaning as that of the aforementioned L¹⁵, with thesame preferable range.

n⁷¹ has the same meaning as that of the aforementioned n¹¹, with thesame preferable range.

Z⁷¹, Z⁷², Z⁷³, Z⁷⁴, Z⁷⁵, and Z⁷⁶ each represent a substituted orunsubstituted carbon atom or a nitrogen atom, with the substituted orunsubstituted carbon atom being preferable. Examples of the substituenton the carbon atom include those explained in the aforementioned R²¹.Further, Z⁷¹ and Z⁷², and Z⁷³ and Z⁷⁴ each may bond to each other via alinking group, to form a condensed ring (for example, a benzo-condensedring, a pyridine-condensed ring).

R⁷¹, R⁷², R⁷³, and R⁷⁴ each have the same meanings as those of theaforementioned R²¹, R²², R²³, and R²⁴ in formula (2), with the samepreferable ranges.

The compound represented by formula (11) will be described below.

R^(C1) and R^(C2) each represent a hydrogen atom or a substituent. Thesubstituent represents an alkyl group or aryl group illustrated asexamples of the substituent of R²¹ to R²⁴ in formula (2). Thesubstituents represented by R^(C3), R^(C4), R^(C5), and R^(C6) also havethe same meanings as those of R²¹ to R²⁴ in formula (2). n^(C3) andn^(C6) each represent an integer of 0 to 3. n^(C4) and n^(C5) eachrepresent an integer of 0 to 4. When there are two or more R^(C3)s,R^(C4)s, R^(C) s or R^(C6)s, the respective R^(C3)s, R^(C4)s, R^(C5)s orR^(C6)s may be the same or different from each other, and they may bondto each other to form a ring respectively. R^(C3), R^(C4), R^(C5), andR^(C6) each are preferably an alkyl group, an aryl group, a hetero arylgroup, and a halogen atom.

Next, the compound represented by formula (10) will be explained.

M^(B1), Y^(B2), Y^(B3), R^(B1), R^(B2), R^(B3), R^(B4), L^(B5), n^(B3),X^(B1), and X^(B2) each have the same meanings as M²¹, Y²², Y²³, R²¹,R²², R²³, R²⁴, L²⁵, n²¹, X²¹, and X²² in formula (2) respectively, withthe same preferable ranges. Y^(B1) represents a linking group that isthe same as Y²¹ in formula (2), preferably a vinyl group thatsubstitutes with 1- and 2-positions, a phenylene ring, a pyridine ring,a pyrazine ring, a pyrimidine ring or a methylene group having 2 to 8carbon atoms. R^(B5) and R^(B6) each represent a hydrogen atom or asubstituent. The substituent represents an alkyl group, aryl group orheterocyclic group illustrated as examples of the substituent of R²¹ toR²⁴ in formula (2). However, Y^(B1) does not link to R^(B5) or R^(B6).n^(B1) and n^(B2) each represent an integer of 0 to 1.

Next, the compound represented by formula (12) will be explained.

The substituents represented by R^(D1), R^(D2), R^(D3), and R^(D4) eachhave the same meanings as R^(B5) and R^(B6) in formula (10) with thesame preferable ranges. n^(D1) and n^(D2) each represent an integer of 0to 4. Y^(D1) represents a vinyl group that substitutes with 1- and2-positions, a phenylene ring, a pyridine ring, a pyrazine ring, apyrimidine ring or a methylene group having 1 to 8 carbon atoms.

A preferable embodiment of the metal complex containing a tridentateligand according to the present invention is illustrated by formula (8).

Next, the compound represented by formula (8) will be described.

M⁸¹ has the same meaning as that of the aforementioned M¹¹, with thesame preferable range.

L⁸¹, L⁸², and L⁸³ have the same meanings as those of the aforementionedL¹¹, L¹², and L¹⁴, respectively, with the same preferable ranges.

Y⁸¹ and Y⁸² have the same meanings as those of the aforementioned Y¹¹and Y¹², respectively, with the same preferable ranges.

L⁸⁵ represents a ligand to coordinate to M⁸¹. L⁸⁵ is preferably amonodentate to tridentate ligand, and more preferably a monodentate totridentate anionic ligand. The monodentate to tridentate anionic ligandis not particularly restricted, but preferably a halogen ligand, atridentate ligand formed by L⁸¹, Y⁸¹, L⁸², Y⁸², and L⁸³, and morepreferably a tridentate ligand formed by L⁸¹, Y⁸³, L⁸², Y⁸², and L⁸³.L⁸⁵ does not directly bond to L⁸¹ or L⁸³, but bonds to via the metal.The coordination numbers and ligand numbers do not exceed thecoordination number of the metal.

n⁸¹ represents from 0 to 5. When M⁸¹ is a metal that has a coordinationnumber of 4, n⁸¹ is 1 and L⁸⁵ is a monodentate ligand. When M⁸¹ is ametal that has a coordination number of 6, n⁸¹ is preferably from 1 to3, more preferably 1 or 3, and furthermore preferably 1. When M⁸¹ is ametal that has a coordination number of 6 and n⁸¹ is 1, L⁸⁵ is atridentate ligand. When M⁸¹ is a metal that has a coordination number of6 and n⁸¹ is 2, L⁸⁵s are a monodentate ligand and a bidentate ligand.When M⁸¹ is a metal that has a coordination number of 6 and n⁸¹ is 3,L⁸⁵ is a monodentate ligand. When M⁸¹ is a metal that has a coordinationnumber of 8, n⁸¹ is preferably from 1 to 5, more preferably 1 or 2, andfurthermore preferably 1. When M⁸¹ is a metal that has a coordinationnumber of 8 and n⁸¹ is 1, L⁸⁵ is a pentadentate ligand; when n⁸¹ is 2,L⁸⁵s are a tridentate ligand and a bidentate ligand; when n⁸¹ is 3, L⁸⁵sare a tridentate ligand and two monodentate ligands, or they are twobidentate ligands and a monodentate ligand; when n⁸¹ is 4, L⁸⁵s are abidentate ligand and three monodentate ligands; when n⁸¹ is 5, L⁸⁵s arefive monodentate ligands. When n⁸¹ is 2 or more, plural L⁸⁵s may be thesame or different from each other.

A preferable embodiment of the compound represented by formula (8) iswhen L⁸¹, L⁸² and L⁸³ in formula (8) each represent an aromaticcarbocycle or heterocycle to coordinate to M⁸¹ via a carbon atom, or anitrogen-containing heterocycle to coordinate to M⁸¹ via a nitrogenatom, providing that at least one of L⁸¹, L⁸² and L⁸³ is saidnitrogen-containing heterocycle. Examples of the aromatic carbocycle orheterocycle to coordinate to M⁸¹ via a carbon atom, andnitrogen-containing heterocycle to coordinate to M⁸¹ via a nitrogen atomare the same as the examples of the ligands to coordinate to M¹¹ via acarbon atom and the ligands to coordinate to M¹¹ via a nitrogen atom,which are illustrated in formula (1), with the same preferable ranges.Y⁸¹ and Y⁸² each are preferably a single bond or a methylene group.

Other preferable embodiments of the compound represented by formula (8)are those represented by formula (13) or (14).

Next, the compound represented by formula (13) will be described.

M⁹¹ has the same meaning as that of the aforementioned M⁸¹, with thesame preferable range.

Q⁹¹ and Q⁹² each represent a group to form a nitrogen-containingheterocycle (a ring containing a nitrogen to coordinate to M⁹¹). Thenitrogen-containing heterocycle formed by Q⁹¹ or Q⁹² is not particularlyrestricted, but preferably a pyridine, pyrazine, pyrimidine, pyridazine,triazine, thiazole, oxazole, pyrrole, pyrazole, imidazole, or triazolering or a condensed ring containing any of these rings (e.g., quinoline,benzoxazole, benzimidazole, and indolenine rings); or a tautomer of anyof these rings.

The nitrogen-containing heterocycle formed by Q⁹¹ or Q⁹² is preferably apyridine, pyrazole, thiazole, imidazole, or pyrrole ring or a condensedring containing any of these rings (e.g., quinoline, benzothiazole,benzimidazole, and indolenine rings) or a tautomer of any of theserings, more preferably a pyridine or pyrrole ring or a condensed ringcontaining any of these rings (e.g., quinoline ring) or a tautomer ofany of these rings, still more preferably a pyridine ring and acondensed ring containing a pyridine ring, and particularly preferably apyridine ring.

Q⁹³ represents a group to form a nitrogen-containing heterocycle (a ringcontaining a nitrogen to coordinate to M⁹¹). The nitrogen-containingheterocycle formed by Q⁹³ is not particularly restricted, but preferablya tautomer of a pyrrole, imidazole or triazole ring or a condensed ringcontaining any of these rings (e.g., benzpyrrole ring), and morepreferably a tautomer of a pyrrole ring, or a tautomer of a condensedring containing a pyrrole ring (e.g., benzpyrrole ring).

W⁹¹ and W⁹² have the same meanings as those of the aforementioned W⁵¹and W⁵², respectively, with the same preferable ranges.

L⁹⁵ has the same meaning as that of the aforementioned L⁸⁵, with thesame preferable range.

n⁹¹ has the same meaning as that of the aforementioned n⁸¹, with thesame preferable range.

Next, the compound represented by formula (14) will be described.

M¹⁰¹ has the same meaning as that of the aforementioned M⁸¹, with thesame preferable range.

Q¹⁰² has the same meaning as that of the aforementioned Q²¹, with thesame preferable range.

Q¹⁰¹ has the same meaning as that of the aforementioned Q⁹¹, with thesame preferable range.

Q¹⁰³ represents a group to form an aromatic ring. The aromatic ringformed by Q¹⁰³ is not particularly restricted, but preferably a benzene,furane, thiophene, or pyrrole ring or a condensed ring containing any ofthese rings (e.g., naphthalene ring), more preferably a benzene ring ora condensed ring containing a benzene ring (e.g., naphthalene ring), andparticularly preferably a benzene ring.

Y¹⁰¹ and Y¹⁰² each have the same meanings as those of the aforementionedY²², with the same preferable ranges.

L¹⁰⁵ has the same meaning as that of the aforementioned L⁸⁵, with thesame preferable range.

n¹⁰¹ has the same meaning as that of the aforementioned n⁸¹, with thesame preferable range.

X¹⁰¹ has the same meaning as that of the aforementioned X²¹, with thesame preferable range.

The compound of the present invention may be a low molecular compound,or may be an oligomer compound or a polymer compound having aweight-average molecular weight calculated in terms of polystyrenepreferably in the range of 1,000 to 5,000,000, more preferably in therange of 2,000 to 1,000,000, and furthermore preferably in the range of3,000 to 100,000. With respect to the polymer compound, the structurerepresented, for example, by formula (1) may be contained in a mainchain of the polymer, or in a side chain of the polymer. Further, thepolymer compound may be a homopolymer or a copolymer. The compound ofthe present invention is preferably a low molecular compound.

Another preferable embodiment of the metal complex having a tridentateligand of the present invention is a metal complex represented byformula (X1). Among the metal complexes represented by formula (X1),metal complexes represented by formula (X2) are preferable, and metalcomplexes represented by formula (X3) are more preferable.

The compound represented by formula (X1) will be described.

M^(X1) represents a metal ion. The metal ion is not particularlyrestricted, but a monovalent to trivalent metal ion is preferable, adivalent or trivalent metal ion is more preferable, and a trivalentmetal ion is furthermore preferable. Specifically, platinum, iridium,rhenium, palladium, rhodium, ruthenium, copper, europium, gadolinium,and terbium ions are preferable. Of these ions, platinum, iridium andeuropium ions are more preferable, platinum and iridium ions arefurthermore preferable, and an iridium ion is particularly preferable.

Q^(X11), Q^(X12), Q^(X13), Q^(X14), Q^(X15), and Q^(X16) each representan atom to coordinate to M^(X1) or an atomic group having an atom tocoordinate to M^(X1). When Q^(X11), Q^(X12), Q^(X13), Q^(X14), Q^(X15),or Q^(X16) represents an atom to coordinate to M^(X1), specific examplesof the atom include a carbon atom, a nitrogen atom, an oxygen atom, asilicon atom, a phosphorus atom, and a sulfur atom; and preferably, theatom is a nitrogen atom, an oxygen atom, and a sulfur atom, or aphosphorus atom, and more preferably a nitrogen atom or an oxygen atom.

When Q^(X11), Q^(X12), Q^(X13), Q^(X14), Q^(X15), or Q^(X16) representsan atomic group having an atom to coordinate to M^(X1), examples of theatomic group to coordinate to M^(X1) via a carbon atom include an iminogroup, an aromatic hydrocarbon ring group (e.g., benzene, naphthalene),a heterocyclic ring group (e.g., thiophene, pyridine, pyrazine,pyrimidine, pyridazine, triazine, thiazole, oxazole, pyrrole, imidazole,pyrazole, triazole), a condensed ring including any of these rings, anda tautomer of any of these rings.

Examples of the atomic group to coordinate to M^(X1) via a nitrogen atominclude a nitrogen-containing heterocyclic ring group (e.g., pyridine,pyrazine, pyrimidine, pyridazine, triazine, thiazole, oxazole, pyrrole,imidazole, pyrazole, triazole), an amino group {e.g., an alkylaminogroup (having carbon atoms preferably in the range of 2 to 30, morepreferably in the range of 2 to 20, and particularly preferably in therange of 2 to 10; for example, methylamino), an arylamino group (forexample, phenylamino), an acylamino group (having carbon atomspreferably in the range of 2 to 30, more preferably in the range of 2 to20, and particularly preferably in the range of 2 to 10; for example,acetylamino, benzoylamino), an alkoxycarbonylamino group (having carbonatoms preferably in the range of 2 to 30, more preferably in the rangeof 2 to 20, and particularly preferably in the range of 2 to 12; forexample, methoxycarbonylamino), an aryloxycarbonylamino group (havingcarbon atoms preferably in the range of 7 to 30, more preferably in therange of 7 to 20, and particularly preferably in the range of 7 to 12;for example, phenyloxycarbonylamino), a sulfonylamino group (havingcarbon atoms preferably in the range of 1 to 30, more preferably in therange of 1 to 20, and particularly preferably in the range of 1 to 12;for example, methane sulfonylamino, benzene sulfonylamino)}, and animino group. These groups may be further substituted with a substituent.

Examples of the atomic group to coordinate to M^(X1) via an oxygen atominclude an alkoxy group (having carbon atoms preferably in the range of1 to 30, more preferably in the range of 1 to 20, and particularlypreferably in the range of 1 to 10; for example, methoxy, ethoxy,butoxy, 2-ethylhexyloxy), an aryloxy group (having carbon atomspreferably in the range of 6 to 30, more preferably in the range of 6 to20, and particularly preferably in the range of 6 to 12; for example,phenyloxy, 1-naphthyloxy, 2-naphthyloxy), a heterocyclic oxy group(having carbon atoms preferably in the range of 1 to 30, more preferablyin the range of 1 to 20, and particularly preferably in the range of 1to 12; for example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy),an acyloxy group (having carbon atoms preferably in the range of 2 to30, more preferably in the range of 2 to 20, and particularly preferablyin the range of 2 to 10; for example, acetoxy, benzoyloxy), a silyloxygroup (having carbon atoms preferably in the range of 3 to 40, morepreferably in the range of 3 to 30, and particularly preferably in therange of 3 to 24; for example, trimethylsilyloxy, triphenylsilyloxy), acarbonyl group (for example, ketone group, ester group, amide group),and an ether group (for example, dialkylether group, diarylether group,furyl group).

Examples of the atomic group to coordinate to M^(X1) via a sulfur atominclude an alkylthio group (having carbon atoms preferably in the rangeof 1 to 30, more preferably in the range of 1 to 20, and particularlypreferably in the range of 1 to 12; for example, methylthio, ethylthio),an arylthio group (having carbon atoms preferably in the range of 6 to30, more preferably in the range of 6 to 20, and particularly preferablyin the range of 6 to 12; for example, phenylthio), a heterocyclic thiogroup (having carbon atoms preferably in the range of 1 to 30, morepreferably in the range of 1 to 20, and particularly preferably in therange of 1 to 12; for example, pyridylthio, 2-benzimidazolylthio,2-benzoxazolylthio, 2-benzthiazolylthio), a thiocarbonyl group (forexample, thioketone group, thioester group), and a thioether group (forexample, dialkylthioether group, diarylthioether group, thiofurylgroup).

Examples of the atomic group to coordinate to M^(X1) via a phosphorusatom include a dialkylphosphino group, a diarylphosphino group, atrialkylphosphine, a triarylphosphine, a phosphinine group. These groupsmay be further substituted.

As the atomic group represented by Q^(X11), Q^(X12), Q^(X13), Q^(X14),Q^(X15), or Q^(X16), preferred are an aromatic hydrocarbon ring group tocoordinate via a carbon atom, an aromatic heterocycle group tocoordinate via a carbon atom, a nitrogen-containing aromatic heterocyclegroup to coordinate via a nitrogen atom, an alkyloxy group, an aryloxygroup, an alkylthio group, an arylthio group, a dialkylphosphino group;more preferred are an aromatic hydrocarbon ring group to coordinate viaa carbon atom, an aromatic heterocycle group to coordinate via a carbonatom, and a nitrogen-containing aromatic heterocycle group.

L^(X11), L^(X12), L^(X13), and L^(X14) each represent a single bond, adouble bond, or a linking group. The linking group is not particularlyrestricted. Preferred examples of the linking group include a linkinggroup comprising any of carbon, nitrogen, oxygen, sulfur, and siliconatoms. Specific examples of the linking group are shown below, but thepresent invention is not limited to these.

These linking groups may be further substituted by a substituent.Examples of the substituent include those explained as the substituentsrepresented by R²¹ to R²⁴ in formula (2), with the same preferablerange. As L^(X11), L^(X12), L^(X13) or L^(X14), preferred are a singlebond, a dimethylmethylene group, a dimethylsilylene group.

The metal complex represented by formula (X1) is more preferably a metalcomplex represented by formula (X2). Next, the metal complex representedby formula (X2) will be described below.

M^(X2) has the same meaning as that of the aforementioned M^(X1) informula (X1), with the same preferable range. Y^(X21), Y^(X22), Y^(X23),Y^(X24), Y^(X25), and Y^(X26) each represent an atom to coordinate toM^(X2). A bond between Y^(X21) and M^(X2), a bond between Y^(X22) andM^(X2), a bond between Y^(X23) and M^(X2), a bond between Y^(X24) andM^(X2), a bond between Y^(X25) and M^(X2), and a bond between Y^(X26)and M^(X2) may each be a coordinate bond or a covalent bond. Specificexamples of T^(X21), Y^(X22), Y^(X23), Y^(X24), Y^(X25), or Y^(X26)include a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, aphosphorus atom, and a silicon atom; and preferred are a carbon atom anda nitrogen atom. Each of Q^(X21), Q^(X22), Q^(X23), Q^(X24), Q^(X25),and Q^(X26) respectively represents an atomic group necessary to form anaromatic hydrocarbon ring or aromatic heterocycle together with each ofY^(X21), Y^(X22), Y^(X23), Y^(X24), Y^(X25), and Y^(X26), respectively.Examples of the aromatic hydrocarbon ring or aromatic heterocycle formedby these groups include benzene, pyridine, pyrazine, pyrimidine,pyridazine, triazine, pyrrole, pyrazole, imidazole, triazole, oxazole,thiazole, oxadiazole, thiadiazole, thiophene, and furane rings.Preferred are benzene, pyridine, pyrazine, pyrimidine, pyrazole,imidazole, and triazole rings; more preferred are benzene, pyridine,pyrazine, pyrazole, and triazole rings; and particularly preferred arebenzene and pyridine rings. These rings may further include a condensedring, or may have a substituent.

L^(X21), L^(X22), L^(X23), and L^(X24) have the same meanings as thoseof the aforementioned L^(X11), L^(X12), L^(X13), and L^(X14) in formula(X1), with the same preferable ranges.

The metal complex represented by formula (X1) is furthermore preferablya metal complex represented by formula (X3). Next, the metal complexrepresented by formula (X3) will be described below.

M^(X3) has the same meaning as that of the aforementioned M^(X1) informula (X1), with the same preferable range. Y^(X31), Y^(X32), Y^(X33),Y^(X34), Y^(X35), and Y^(X36) each represent an atom to coordinate toM^(X3). A bond between Y^(X31) and M^(X3), a bond between Y^(X32) andM^(X3), a bond between Y^(X33) and M^(X3), a bond between Y^(X34) andN^(X3), a bond between Y^(X35) and M^(X3), and a bond between Y^(X36)and M^(X3) may each be a coordinate bond or a covalent bond. Specificexamples of Y^(X31), Y^(X32), Y^(X33), Y^(X34), Y^(X35), or Y^(X36)include a carbon atom, a nitrogen atom, and a phosphorus atom; andpreferred are a carbon atom and a nitrogen atom. L^(X31), L^(X32),L^(X33), and L^(X34) have the same meanings as those of theaforementioned L^(X11), L^(X12), L^(X13), and L^(X14) in formula (X1),with the same preferable ranges.

Specific examples of the compound of the present invention are shownbelow, but the present invention is not limited to these compounds.

(Synthesis Methods of the Metal Complexes According to the PresentInvention)

The metal complexes according to the present invention (i.e., compoundsrepresented by any one of formulas (1) to (14) and formulas (X1) to(X3)) can be synthesized according to various methods.

For example, the compounds can be obtained by reacting a ligand or itsdissociated product with a metal compound, in the presence of a solvent(e.g., a halogen-series solvent, an alcohol-series solvent, anether-series solvent, an ester-series solvent, a ketone-series solvent,a nitrile-series solvent, an amide-series solvent, a sulfone-seriessolvent, a sulfoxide-series solvent and water), or in the absence of asolvent, in the presence of a base (various inorganic or organic bases,such as sodium methoxide, potassium t-butoxide, triethylamine andpotassium carbonate), or in the absence of a base, at room temperatureor below, or alternatively by heating (in addition to an ordinaryheating, a method of heating by means of microwave is also effective).

A reaction time that is applied in synthesizing the metal complex of thepresent invention varies depending upon activity of raw materials, andthere is no particular limitation as to the reaction time, butpreferably the reaction time is in the range of from 1 minute to 5 days,more preferably in the range of from 5 minutes to 3 days, andfurthermore preferably in the range of from 10 minutes to 1 day.

A reaction temperature that is applied in synthesizing the metal complexof the present invention varies depending upon reaction activity, andthere is no particular limitation as to the reaction temperature, butthe reaction temperature is preferably in the range of from 0° C. to300° C., more preferably in the range of from 5° C. to 250° C., andfurthermore preferably in the range of from 10° C. to 200° C.

The metal complexes of the present invention, such as the compoundsrepresented by formulae (1) to (14) and formulae (X1) to (X3), can besynthesized by properly selecting a ligand that forms a partialstructure of the objective complex. For example, the compoundsrepresented by formula (3) can be synthesized by adding a ligand such as6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl or its derivatives (ligandssuch as 2,9-bis(2-hydroxyphenyl)-1,10-phenanthroline,2,9-bis(2-hydroxyphenyl)-4,7-diphenyl-1,10-phenanthroline and6,6′-bis(2-hydroxy-5-tert-butylphenyl)-2,2′-bipyridyl) in an amount ofpreferably from 0.1 to 10 equivalents, more preferably from 0.3 to 6equivalents, furthermore preferably from 0.5 to 4 equivalents, to ametal compound, respectively. The reaction solvent, the reaction timeand the reaction temperature that are used in the synthesis method ofthe compounds represented by formula (3) are each the same as describedin the above-mentioned synthesis of the metal complexes of the presentinvention.

The derivatives of the 6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl ligandcan be synthesized according to various known methods. For example, theycan be synthesized by subjecting 2,2′-bipyridyl derivatives (e.g.,1,10-phenanthroline) and anisole derivatives (e.g., 4-fluoroanisole) toa reaction according to the method described in Journal of OrganicChemistry, 741, 11 (1946). Alternatively, they can be synthesized bysubjecting halogenated 2,2′-bipyridyl derivatives (e.g.,2,9-dibromo-1,10-phenanthroline) and 2-methoxyphenylboronic acidderivatives (e.g., 2-methoxy-5-fluorophenylboronic acid) as startingmaterials, to the Suzuki coupling reaction, followed by release of themethyl group as a protecting group according to, for example, the methoddescribed in Journal of organic Chemistry, 741, 11 (1946), or the methodof heating the reaction mixture in the presence of pyridinehydrochloride. Alternatively, they can be synthesized by subjecting2,2′-bipyridyl boronic acid derivatives (e.g.,6,6′-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolyl)-2,2′-bipyridyl) andhalogenated anisole derivatives (e.g., 2-bromoanisole) as startingmaterials, to the Suzuki coupling reaction, followed by release of themethyl group as a protecting group according to, for example, the methoddescribed in Journal of Organic Chemistry, 741, 11 (1946), or the methodof heating the reaction mixture in the presence of pyridinehydrochloride.

The luminescent devices containing the metal complex of the presentinvention are explained below.

The luminescent devices of the present invention are not particularlyrestricted, for example, in their system, driving method and form inuse, so long as the metal complexes of the present invention are usedtherein. As a typical luminescent device, organic EL(electroluminescent) devices are recited.

The luminescent device of the present invention is an organicelectroluminescent device comprising a pair of electrodes and at leastone organic layer including a luminescent layer between the pair ofelectrodes. Said organic layer preferably contains a hole-transportinglayer and a luminescent layer, and further at least one layer selectedfrom an exciton-blocking layer, a hole injection layer, a hole-blockinglayer and an electron-transporting layer.

The luminescent device of the present invention preferably has, betweena negative electrode and a luminescent layer, a layer containing acompound having ionization potential of 5.9 eV or more (more preferably6.0 eV or more), and more preferably has an electron-transporting layerhaving ionization potential of 5.9 eV or more.

A method of forming an organic layer of the luminescent devicecontaining the metal complex of the present invention is notparticularly limited. As the method, various methods, such as aresistance heating vapor deposition method, an electron-beam method, asputtering method, a molecular lamination method, a coating method(e.g., a spray coating method, dip coating method, dipping method, rollcoating method, gravure coating method, reverse coating method, rollbrushing method, air knife coating method, curtain coating method, spincoating method, flow coating method, bar coating method, micro gravurecoating method, air doctor coating method, blade coating method, squeezecoating method, transfer roll coating method, kiss coating method, castcoating method, extrusion coating method, wire bar coating method andscreen coating method), an inkjet method, a printing method, and atransfer method, can be adopted. From the viewpoints of characteristicsand production, a resistance heating vapor deposition method, a coatingmethod and a transfer method are preferable.

The positive electrode is to supply positive holes to a positivehole-injecting layer, a positive hole-transporting layer, a luminescentlayer, and the like; and metals, alloys, metal oxides, electricallyconductive compounds, or mixtures of these can be used therefor, andmaterials having a work function of 4 eV or more are preferably used.Specific examples of the materials include electrically conductive metaloxides, such as tin oxide, zinc oxide, indium oxide, and indium tinoxide (ITO); metals, such as gold, silver, chromium, and nickel;mixtures or laminations of these metals with electrically conductivemetal oxides; inorganic electrically conductive substances, such ascopper iodide and copper sulfide; organic electrically conductivesubstances, such as polyaniline, polythiophene, and polypyrrole; andlaminations of these materials with ITO. Electrically conductive metaloxides are preferably used, and ITO is particularly preferably used inview of producibility, high conductivity and transparency. The filmthickness of the positive electrode can be selected arbitrarilyaccording to materials to be used, but is generally preferably from 10nm to 5 μm, more preferably from 50 nm to 1 μm, and still morepreferably from 100 nm to 500 nm.

The positive electrode generally comprises a layer(s) formed on asoda-lime glass, non-alkali glass or transparent resin substrate. When aglass substrate is used, non-alkali glass is preferably used forlessening elution of ions from the glass. Further, when soda-lime glassis used, it is preferred to provide a barrier coat such as silica. Thethickness of the substrate is not particularly limited so long as it cansufficiently maintain mechanical strength. When glass is used, thethickness is generally 0.2 mm or more, preferably 0.7 mm or more.

Various processes are used in the manufacture of the positive electrodeaccording to the materials to be used. In the case of using ITO, forexample, a thin layer film(s) is formed by an electron beam process, asputtering process, a resistance heating vapor deposition process, achemical reaction process (e.g. a sol-gel process), or the process ofcoating a dispersion of an indium tin oxide.

It is possible to reduce the driving voltage or increase the luminescentefficacy of the device or element, by a process such as washing of thepositive electrode. In the case of using ITO, for example, UV-ozoneprocessing or plasma treatment is effective.

The negative electrode is to supply electrons to an electron-injectinglayer, an electron-transporting layer, a luminescent layer, and thelike, and the negative electrode is selected taking into considerationthe adhesion with the layer adjacent to the negative electrode, such asan electron-injecting layer, electron-transporting layer, or luminescentlayer; ionization potential, stability, and the like. As materials ofthe negative electrode, metals, alloys, metal halides, metal oxides,electrically conductive compounds, or mixtures of these materials can beused. Specific examples include alkali metals (e.g., Li, Na, K) or theirfluorides or oxides, alkaline earth metals (e.g., Mg, Ca) or theirfluorides or oxides, gold, silver, lead, aluminum, sodium-potassiumalloys or mixed metals thereof, lithium-aluminum alloys or mixed metalsthereof, magnesium-silver alloys or mixed metals thereof, and rare earthmetals, such as indium, ytterbium, and the like; preferably materialshaving a work function of 4 eV or less, and more preferably aluminum,lithium-aluminum alloys or mixed metals thereof, and magnesium-silveralloys or mixed metals thereof. The negative electrode structure may benot only a single layer of the aforementioned compound or mixturethereof, but also a laminate comprised of the aforementioned compound ormixture thereof. For example, laminate structures of aluminum/lithiumfluoride, or aluminum/lithium oxide are preferable. The film thicknessof the negative electrode can be selected arbitrarily according tomaterials to be used, but is generally preferably from 10 nm to 5 μm,more preferably from 50 nm to 1 μm, and still more preferably from 100nm to 1 μm.

Processes such as an electron beam process, a sputtering process, aresistance heating vapor deposition process, a coating process, and atransfer method are used in the manufacture of the negative electrode,and a single metal can be vapor-deposited or two or more components canbe vapor-deposited at the same time. Further, a plurality of metals canbe vapor-deposited at the same time to form an alloy electrode,alternatively a previously prepared alloy can be vapor-deposited.

It is preferred that the sheet resistance of the positive electrode andthe negative electrode be low, preferably several hundreds Ω/□ or less.

The material for a luminescent layer may be any of materials capable offorming a layer that can function so as to accept both injection ofholes from the positive electrode, the hole injection layer or thehole-transporting layer and injection of electrons from the negativeelectrode, the electron injection layer or the electron-transportinglayer when electric field is applied thereto, or to let the chargesinjected therein to transfer, or to enable the emission of light byproviding a cite for recombining the holes and the electrons. Besidesthe compound of the present invention, examples of the material includevarious metal complexes typically exemplified by metal complex or rareearth complex of benzoxazole derivatives, benzimidazole derivatives,benzothiazole derivatives, styrylbenzene derivatives, polyphenylderivatives, diphenylbutadiene derivatives, tetraphenylbutadienederivatives, naphthalimide derivatives, coumarin derivatives, perylenederivatives, perinone derivatives, oxadiazole derivatives, aldazinederivatives, pyraridine derivatives, cyclopentadiene derivatives,bisstyrylanthracene derivatives, quinacridone derivatives,pyrrolopyridine derivatives, thiadiazolopyridine derivatives,cyclopentadiene derivatives, styrylamine derivatives, aromaticdimethylidyne compounds, and 8-quinolinol derivatives; polymericcompounds, such as polythiophene, polyphenylene, andpolyphenylenevinylene; organic silanes; transition metal complexes(e.g., iridium trisphenylpyridine and platinum porphyrin, andderivatives thereof).

As the host material of the luminescent layer, there are preferablyillustrated amine compounds (for example, triarylamine compounds); metalchelate oxynoid compounds (compounds having a metal-oxygen bond) inwhich the metal is aluminum, zinc or transition metals, and a ligand is8-hydroxyquinoline derivatives, 2-(2-pyridino)phenol derivatives or thelike; polyarylene compounds (for example, hexaphenyl benzenederivatives), condensed aromatic carbocyclic compounds and non-complexaromatic nitrogen-containing heterocyclic compounds (for example,carbazole derivatives). The host material of the luminescent layer maybe a mixture of at least two compounds.

The film thickness of the luminescent layer is not particularlyrestricted, but it is generally preferably from 1 nm to 5 μm, morepreferably from 5 nm to 1 μm, and still more preferably from 10 nm to500 nm.

Although there is no particular limitation on methods for forming theluminescent (light emitting) layers, methods such as resistance heatingvapor deposition, electron beam processing, sputtering, molecularlamination, coating, inkjet process, printing, LB (Langmuir-Blodgett)processing, and transfer process can be used. Preferred are a resistanceheating vapor deposition method and a coating method.

The luminescent layer may be formed of a single compound, or two or morekinds of compounds. Further, the luminescent layer may have a singlelayer structure, or a multiple-layer structure made of at least twolayers. Each layer may emit light of a different luminescent color sothat the luminescent layer can emit, for example, a white light. Asingle luminescent layer may emit a white light. When the luminescentlayer is a plurality of layers, each layer may be formed of a singlematerial, or at least two compounds or materials.

Materials of the positive hole-injecting layer and the positivehole-transporting layer are sufficient if they have any of the functionsof injecting positive holes from the positive electrode, transportingpositive holes, and blocking the electrons injected from the negativeelectrode. Specific examples of the materials include carbazolederivatives, triazole derivatives, oxazole derivatives, oxadiazolederivatives, imidazole derivatives, polyarylalkane derivatives,pyrazoline derivatives, pyrazolone derivatives, phenylenediaminederivatives, arylamine derivatives, amino-substituted chalconederivatives, styrylanthracene derivatives, fluorenone derivatives,hydrazone derivatives, stilbene derivatives, silazane derivatives,aromatic tertiary amine compounds, styrylamine compounds, aromaticdimethylidyne-series compounds, porphyrin-series compounds,polysilane-series compounds, poly(N-vinylcarbazole) derivatives,aniline-series copolymers, electrically conductive high molecular weightoligomers, such as thiophene oligomers and polythiophene; organic silanecompounds, carbon film, and the compounds of the present invention. Thefilm thickness of the hole-injection layer is not particularly limited,and in general, it is preferably from 1 nm to 5 μm, more preferably from5 nm to 1 μm, and further preferably from 10 nm to 500 nm. The filmthickness of the hole-transporting layer is not particularly limited,and in general, it is preferably from 1 nm to 5 μm, more preferably from5 nm to 1 μm, and further preferably from 10 nm to 500 nm. Thehole-injecting layer or hole-transporting layer may have a single layerstructure of one kind or two or more kinds of the above materials, oralternatively, a multilayer structure comprising plural layers havingthe same composition or different compositions.

As the materials for the hole-injunction layer, copper phthalocyanineand star burst-type amine compounds are preferable.

Examples of a method of forming the hole-injecting layer and thehole-transporting layer include a vacuum deposition method, an LBmethod, the process of dissolving or dispersing the above-describedhole-injecting/transporting material in a solvent and coating; an inkjet method, a printing method, and a transfer method. In the case of acoating process, a positive hole-injecting/transporting material can bedissolved or dispersed with a resin component. Examples of such resincomponents include polyvinyl chloride, polycarbonate, polystyrene,polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone,polyphenylene oxide, polybutadiene, poly(N-vinylcarbazole), hydrocarbonresin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinylacetate, ABS resin, polyurethane, melamine resin, unsaturated polyesterresin, alkyd resin, epoxy resin, silicone resin, and the like.

Materials of the electron-injecting layer and the electron-transportinglayer are sufficient if they have any of the functions of injectingelectrons from the negative electrode, transporting electrons, andblocking (as a barrier off) the positive holes injected from thepositive electrode. As the materials for the electron-transportinglayer, metal chelate oxynoid compounds, polyarylene compounds, condensedaromatic carbocyclic compounds and non-complex aromatic heterocycliccompounds are preferable. Specific examples of the materials includetriazole derivatives, oxazole derivatives, oxadiazole derivatives,imidazole derivatives, fluorenone derivatives, anthraquinodimethanederivatives, anthrone derivatives, diphenylquinone derivatives,thiopyrandioxide derivatives, carbodiimide derivatives,fluorenylidenemethane derivatives, distyrylpyrazine derivatives,tetracarboxylic acid anhydrides of aromatic rings such as naphthaleneand perylene, phthalocyanine derivatives, various metal complexesrepresented by metal complexes of 8-quinolinol derivatives,metallophthalocyanines and metal complexes having benzoxazole orbenzothiazole ligands, organosilane compounds. The film thickness of theelectron-injecting layer and the electron-transporting layer is notparticularly restricted, but it is generally preferably from 1 nm to 5μm, more preferably from 5 nm to 1 μm, and still more preferably from 10nm to 500 nm. The electron-injecting layer and the electron-transportinglayer may be single layer structure comprising one or two or more of theabove materials, or may be multilayer structure comprising a pluralityof layers of the same composition or different compositions.

Examples of a method of forming the electron injecting layer and theelectron transporting layer include a vacuum deposition method, an LBmethod, the process of dissolving or dispersing the above-describedelectron-injecting/transporting material in a solvent and coating; anink jet method, a printing method, and a transfer method. In the case ofa coating process, an electron injecting/transporting material can bedissolved or dispersed with a resin component. As the resin components,for example, those exemplified in the positive hole-injecting andtransporting layers can be applied.

Materials of the protective layer are sufficient if they have thefunction of preventing substances which accelerate deterioration of thedevice or element, such as water or oxygen, from entering the device orelement. Specific examples of the materials include metals such as In,Sn, Pb, Au, Cu, Ag, Al, Ti and Ni; metal oxides such as MgO, SiO, SiO₂,Al₂O₃, GeO, NiO, CaO, BaO, Fe₂O₃, Y₂O₃, and TiO₂; metal fluorides suchas MgF₂, LiF, AlF₃, and CaF₂; metal nitrides such as SiN_(x) andSiO_(x)N_(y); polyethylene, polypropylene, polymethyl methacrylate,polyimide, polyurea, polytetrafluoroethylene,polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymers ofchlorotrifluoroethylene and dichlorodifluoroethylene, copolymersprepared by copolymerizing a monomer mixture of tetrafluoroethylene andat least one comonomer, fluorine-containing copolymers having cyclicstructures on the main chain, water-absorbing substances having a waterabsorption rate of at least 1%, and moisture-proof substances having awater absorption rate of at most 0.1%.

The forming process of the protective layer is also not particularlyrestricted, and, for example, a vacuum deposition process, a sputteringprocess, a reactive sputtering process, an MBE (molecular beam epitaxy)process, a cluster ion beam process, an ion-plating process, a plasmapolymerization process (a high frequency exciting ion-plating process),a plasma CVD (chemical vapor deposition) process, a laser CVD process, aheat CVD process, a gas source CVD process, a coating process, aprinting process, and a transfer process can be applied.

EXAMPLES

The present invention will be explained in more detail with reference tothe examples below, but the embodiments for carrying out the presentinvention should not be construed to be limited to these.

Synthesis of Compound (1)

To 6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl (0.1 g) and PtCl₂ (0.16 g),benzonitrile (10 ml) was added and heated under reflux for 3 hours undera nitrogen atmosphere. After cooling the reaction solution to a roomtemperature, methanol was added to the reaction solution to causeprecipitation, and the precipitate was suction filtered. The solidobtained was purified using silica gel chromatography (chloroform as adeveloping solvent), to obtain 0.06 g of Compound (1). The structure ofCompound (1) was identified by mass spectrometry. Upon irradiation of UVlight to a chloroform solution containing Compound (1) under a nitrogenatmosphere, reddish orange-colored light-emission (λ_(max)=624 nm) wasobtained.

6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl used as a starting material inthe aforementioned reaction, can be synthesized according to the methoddescribed in Journal of Organic Chemistry, 741, 11 (1946).Alternatively, the compound can be synthesized according to the schemedescribed below.

Synthesis of 6,6′-bis(2-methoxyphenyl)-2,2′-bipyridyl

To a mixture of 6,6′-dibromo-2,2′-bipyridyl (1.15 g), 2-methoxyphenylboronic acid (1.45 g), PPh₃ (0.167 g), potassium carbonate (2.2 g) andPd(OAc)₂ (36 mg), dimethoxyethane (10 ml) and water (10 ml) were addedand heated under reflux for 4 hours under a nitrogen atmosphere. Aftercooling the reaction solution to a room temperature, chloroform (20 ml)and water (20 ml) were added to the reaction solution for separation.Thereafter, the organic layer was concentrated. Purification by silicagel chromatography (chloroform as a developing solvent) was carried out,to obtain 0.9 g of 6,6′-bis(2-methoxyphenyl)-2,2′-bipyridyl.

Synthesis of 6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl

A mixture of a 6,6′-bis(2-methoxyphenyl)-2,2′-bipyridyl ligand (0.3 g)and pyridine hydrochloride (10 g) was heated for 4 hours at 160° C.under a nitrogen atmosphere. After cooling the reaction solution to aroom temperature, chloroform (20 ml) and water (20 ml) were added to thereaction solution for separation. Thereafter, the organic layer wasconcentrated. Purification by silica gel chromatography (chloroform as adeveloping solvent) was carried out, to obtain 0.2 g of6,6′-bis(2-hydroxyphenyl)-2,2′-bipyridyl.

Synthesis schemes of compound (79) and compound (88) that weresynthesized according to the same method as mentioned above are shownbelow.

λ_(max) of light emitted from Compound (79) in dichloroethane was 512nm, while λ_(max) of light emitted from Compound (88) in dichloroethanewas 620 nm.

The compounds represented by formula (11) or (12) in which thesubstituents each are an alkyl group, an aryl group, a heteroaryl group,or a halogen atom, can be also synthesized according to theaforementioned method.

Comparative Example 1

A cleaned ITO substrate was placed in a vacuum evaporator, and onto thesubstrate TPD (N,N-diphenyl-N,N-di(m-tolyl)benzidine) was evaporated toform a film having a thickness of 50 nm, then PtOEP (octaethyl porphyrinplatinum complex) and Compound A (a ratio by mass of 1:17) wereco-evaporated to form a film having a thickness of 36 nm, and thenCompound A was evaporated to form a film having a thickness of 36 nm.Then, a patterned mask (for adjusting each emission area to 4 mm×5 mm)was set on the organic thin layers, and further thereon, inside thevacuum evaporator, lithium fluoride was evaporated to form a film havinga thickness of 3 nm, followed by deposition of a 400 nm-thick aluminum.

The thus produced EL device was subjected to luminescence by applyingthereto a DC constant voltage by means of a source measure unit, Model2400 (trade name), made by Toyo Technica Co., Ltd. and the luminancethat the EL device showed was measured using a luminometer BM-8 (tradename), made by Topcon Co. As a result of the measurement, the lightemission that the EL device gave was found to be a luminescence of 200cd/m² with external quantum efficiency of 1.1% and the maximum luminanceof 390 cd/m².

Example 1

A cleaned ITO substrate was placed in a vacuum evaporator, and onto thesubstrate TPD (N,N-diphenyl-N,N-di(m-tolyl)benzidine) was evaporated toform a film having a thickness of 50 nm, then Compound (1) according tothe present invention and Compound A (a ratio by mass of 1:17) wereco-evaporated to form a film having a thickness of 36 nm, and thenCompound B was evaporated to form a film having a thickness of 36 nm.Then, a patterned mask (for adjusting each emission area to 4 mm×5 mm)was set on the organic thin layers, and further thereon, inside thevacuum evaporator, lithium fluoride was evaporated to form a film havinga thickness of 3 nm, followed by deposition of a 400 nm-thick aluminumfilm.

The thus produced EL device was subjected to luminescence by applyingthereto a DC constant voltage by means of a source measure unit, Model2400 (trade name), made by Toyo Technica Co., Ltd. and the luminancethat the EL device showed was measured using a luminometer BM-8 (tradename), made by Topcon Co. As a result of the measurement, the lightemission that the EL device gave was found to be a luminescence of 200cd/m² with external quantum efficiency of 2.8% and the maximum luminanceof 1090 cd/m².

Example 2

A cleaned ITO substrate was placed in a vacuum evaporator, and onto thesubstrate TPD (N,N-diphenyl-N,N-di(m-tolyl)benzidine) was evaporated toform a film having a thickness of 50 nm, then Compound (1) according tothe present invention and Compound A (a ratio by mass of 1:2) wereco-evaporated to form a film having a thickness of 36 nm, and thenCompound B was evaporated to form a film having a thickness of 36 nm inthis order. Then, a patterned mask (for adjusting each emission area to4 mm×5 mm) was set on the organic thin layers, and further thereon,inside the vacuum evaporator, lithium fluoride was evaporated to form afilm having a thickness of 3 nm, followed by deposition of a 400nm-thick aluminum film.

The thus produced EL device was subjected to luminescence by applyingthereto a DC constant voltage by means of a source measure unit, Model2400 (trade name), made by Toyo Technica Co., Ltd. and the luminancethat the EL device showed was measured using a luminometer BM-8 (tradename), made by Topcon Co. As a result of the measurement, the lightemission that the EL device gave was found to be a luminescence of 200cd/m² with external quantum efficiency of 4.4% and the maximum luminanceof 3820 cd/m².

Comparative Example 2

An EL device (Device No-101) was prepared according to the methoddescribed in Example 8 of U.S. Pat. No. 6,653,654 B1.

Comparative Example 3

A cleaned ITO substrate was placed in a vacuum evaporator, and onto thesubstrate α-NPD was evaporated to form a hole-transporting layer havinga thickness of 50 nm. Then Bepp₂ as a host and Compound (65) as aluminescent material were co-evaporated for 0.4 nm/sec and 0.02 nm/secrespectively so as to become 40 nm in film thickness, thereby to form aluminescent layer. Then, a patterned mask (for adjusting each emissionarea to 2 mm×2 mm) was set on the organic thin layers, and furtherthereon, inside the vacuum evaporator, lithium fluoride was evaporatedto form a film having a thickness of 1.5 nm, followed by deposition of a200 nm-thick aluminum film. Subsequently, the device was sealed afterincorporation of a drying agent therein, to prepare an EL device (DeviceNo-102). In addition, another EL device (Device No-103) was prepared inthe same manner as described above, except that the luminescent materialwas replaced with Compound (1).

Example 3

A luminescent layer was formed in the same manner as in ComparativeExample 3, except for changing the film thickness of host to 36 nm.Thereon, compound B was evaporated to form an electron-transportinglayer having a thickness of 36 nm. Then, a patterned mask (for adjustingeach emission area to 2 mm×2 mm) was set on the organic thin layers, andfurther thereon, inside the vacuum evaporator, lithium fluoride wasevaporated to form a film having a thickness of 5 nm, followed bydeposition of a 500 nm-thick aluminum film. Subsequently, the device wassealed after incorporation of a drying agent therein, to prepare an ELdevice (Device No-104). In addition, another EL device (Device No-105)was prepared in the same manner as described above, except that the hostmaterial was replaced with Compound A.

Example 4

A cleaned ITO substrate was placed in a vacuum evaporator, and onto thesubstrate copper phthalocyanine was evaporated to form a film having athickness of 10 nm, and thereon α-NPD was evaporated to be a thicknessof 20 nm thereby to form a hole-transporting layer. Thereon, Compound Aas a host and Compound (1) as a luminescent material were co-evaporatedfor 0.4 nm/sec and 0.02 nm/sec respectively so as to become 30 nm infilm thickness, thereby to form a luminescent layer. On the luminescentlayer, BAlq was evaporated to form a hole-blocking layer having athickness of 10 nm, and then Alq was evaporated to form anelectron-transporting layer having a thickness of 40 nm. Then, apatterned mask (for adjusting each emission area to 2 mm×2 mm) was seton the organic thin layers, and further thereon, inside the vacuumevaporator, lithium fluoride was evaporated to form a film having athickness of 5 nm, followed by deposition of a 500 nm-thick aluminumfilm. Subsequently, the device was sealed after incorporation of adrying agent therein, to prepare an EL device (Device No-201). Inaddition, other EL devices (Device No-202 to 206) were prepared in thesame manner as described above, except for changing the host material asshown in Table 2.

Next, each EL device thus produced was evaluated as shown below:

The EL devices of the present invention and of comparison were subjectedto luminescence by applying thereto a DC constant voltage by means of asource measure unit, Model 2400 (trade name), made by Toyo Technica Co.,Ltd. and the luminance that each EL device showed was measured using aluminometer BM-8 (trade name), made by Topcon Co. and emissionwavelength was measured using a spectrum analyzer PMA-11 (trade name),made by Hamamatsu Photonics KK, to obtain luminous efficiency. Next,durability was evaluated as follows: First, the device was driven at therate of 1 mA/4 mm², and the initial luminance was measured. Then, after200 h low-current driving of the device at the rate of 1 mA/4 mm²,luminance was measured. The maintenance rate of luminance was obtainedby comparing the 200 h luminance with the initial luminance. The resultsare shown in Tables 1 and 2.

TABLE 1 Electron- Luminescent Host transporting material material layerMaintenance Element (Dope (Film (Film rate of Nos. concentration)thickness) thickness) luminance Remarks 101 Compound (65) Bepp₂ — 6%Comparative example 2% (40 nm) (The element described in U.S. Pat. No.6,653,564B1) 102 Compound (65) Bepp₂ — 11% Comparative example 5% (40nm) (The element described in U.S. Pat. No. 6,653,564B1) 103 Compound(1) Bepp₂ — 8% Comparative example 5% (40 nm) (The element described inU.S. Pat. No. 6,653,564B1) 104 Compound (1) Bepp₂ Compound B 21% Thisinvention 5% (36 nm) (36 nm) 105 Compound (1) Compound A Compound B 32%This invention 5% (36 nm) (36 nm) Element configuration: ITO/NPD(50nm)/5 wt % Luminescent material-Host material/Electron-transportingmaterial/LiF—Al

The results demonstrate that the devices of the present invention,containing an electron-transporting layer, exhibited an enhancedmaintenance rate of luminance that led to excellent durability of thedevice, compared with the devices of the Comparative Examples. Inaddition, the durability of the device was further improved by alteringthe host material to a non-complex aromatic heterocyclic compound suchas Compound A.

TABLE 2 Maintenance Element Luminescent Host Light-emission rate of Nos.material material λ_(max) luminance Remarks 201 Compound (1) Compound A615 nm 81% This invention 202 Compound (15) Compound A 586 nm 88% Thisinvention 204 Compound (79) Compound A 509 nm 83% This invention 205Compound (88) Compound A 620 nm 79% This invention 206 Compound (15)BAlq 585 nm 92% This invention Element configuration: ITO/CuPc(10nm)/NPD(20 nm)/5 wt % Luminescent material-Host material(30 nm)/BAlq(10nm)/Alq(40 nm)/LiF—Al

Further, the results demonstrate that the use of both copperphthalocyanine (CuPc), acting as a hole-injunction layer, and BAlq,acting as a hole-blocking layer, further improved on the durability ofthe device, and the compounds of the present invention enabled emittingred light and green light with excellent color purity. Further, thecompounds of the present invention also enable emitting light of ashorter wavelength.

Industrial Applicability

The luminescent devices of the present invention are high in bothexternal quantum efficiency and maximum luminance, and excellent inluminescent characteristics (performances). Further, the luminescentdevices are excellent in durability. The luminescent device of thepresent invention can be preferably used in such fields as displaydevices, displays, backlights, electrophotography, illuminating lightsources, recording light sources, exposing light sources, reading lightsources, signs, signboards, interiors, and optical communications.Further, the compounds of the present invention can be utilized for theelectroluminescent devices, as well as medical usage, brighteningagents, photographic materials, UV absorbing materials, laser dyes,recording media materials, inkjet pigments, color filter dyes, colorconversion filters, and the like. The novel complexes of the presentinvention are suitable for producing such excellent luminescent devicesas described above.

Having described our invention as related to the present embodiments, itis our intention that the invention not be limited by any of the detailsof the description, unless otherwise specified, but rather be construedbroadly within its spirit and scope as set out in the accompanyingclaims.

1. An organic electroluminescent device, comprising a pair of electrodesand at least one organic layer including a luminescent layer between thepair of electrodes, wherein at least one layer between the pair ofelectrodes comprises at least one metal complex having atetradentate-chain structure ligand; wherein the metal complex is acompound represented by formula (9):

wherein, M^(A1) represents a platinum ion; Q^(A1) and Q^(A2) eachrepresent an atomic group necessary to form a nitrogen-containingheterocycle selected from the group consisting of a pyridine ring, apyrazine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, apyrazole ring, an imidazole ring, an oxazole ring, a pyrrole ring, abenzazole ring, a condensed ring containing any of these rings, andtautomers thereof; R^(A1) and R^(A2) represent groups that together forma benzene ring or a pyridine ring; R^(A3) and R^(A4) represent groupsthat together form a benzene ring or a pyridine ring; Y^(A2) and Y^(A3)each represent a single bond; Y^(A1) represents a linking group thatconnects Q^(A1) and Q^(A2) with one carbon atom or one nitrogen atom;L^(A5) represents a ligand to coordinate to M^(A1); n^(A1) represents aninteger of
 0. 2. The organic electroluminescent device as claimed inclaim 1, wherein said metal complex is incorporated in the luminescentlayer.
 3. The organic electroluminescent device as claimed in claim 1,wherein the organic layer comprises at least one luminescent layer and ahole transporting layer, and the organic layer further comprises atleast one layer selected from the group consisting of anexciton-blocking layer, a hole injection layer, a hole-blocking layerand an electron-transporting layer.
 4. The organic electroluminescentdevice as claimed in claim 1, wherein the organic layer comprises atleast one luminescent layer, and a host material of the luminescentlayer is selected from the group consisting of an amine compound, ametal chelate oxynoid compound in which the metal is aluminum, zinc ortransition metals, a polyarylene compound, a condensed aromaticcarbocyclic compound, and a non-complex aromatic heterocyclic compound.5. The organic electroluminescent device as claimed in claim 1, whereinthe organic layer comprises at least one electron-transporting layer inwhich an electron-transporting material is selected from the groupconsisting of a metal chelate oxynoid compound, a polyarylene compound,a condensed aromatic carbocyclic compound and a non-complex aromaticheterocyclic compound.
 6. The organic electroluminescent device asclaimed in claim 1, wherein the organic layer comprises at least oneluminescent layer, and a host material of the luminescent layer iscomposed of at least two compounds.